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74753ec3-f7de-41b5-90fe-d77a48989052
As shown in the figure, in △ABC, ∠A=40°, BC=3. Arcs are drawn with B and C as centers and BC as the radius on the right side of BC, intersecting at point D, and intersecting the extensions of AB and AC at points E and F, respectively. The sum of the lengths of arcs $\overset\frown{DE}$ and $\overset\frown{DF}$ is.
$\frac{5\pi }{3}$
math
cadf4246-7790-49cb-b5e5-f99b44e67c85
As shown in the figure, this is a snake model in computer science. The 4th number from left to right in the 20th row is.
194
math
c8c02455-9bb3-42ad-a37e-2830135167ce
As shown in the figure, a square piece of paper with a side length of $$\quantity{6}{cm}$$ is cut along the dotted lines and then precisely forms a hexagonal prism with a regular hexagon as its base. What is the lateral surface area of this hexagonal prism in ___$$\unit{cm^{2}}$$?
$$36-12\sqrt{3}$$
math
22fa98c7-e398-41b5-87da-9dcfcea5cc7c
The positions of real numbers $$a$$ and $$b$$ on the number line are shown in the figure. Simplify $$|a+b|+|b-a|=$$ ___.
$$-2a$$
math
1cc07f7d-fef3-4737-b8ed-f5c9c0e7c497
A school has two math interest classes, $$A$$ and $$B$$. Class $$A$$ has 40 students, and class $$B$$ has 50 students. In a recent exam, the average score of class $$A$$ is 90 points, and the average score of class $$B$$ is 81 points. What is the average score of the school's math interest classes?
$$85$$
math
105122f7-8104-4f98-a275-ed366bae87cd
As shown in the figure, a particle moves in the first quadrant and on the positive half-axes of the $$x$$ and $$y$$ axes. In the first second, it moves from the origin to $$\left ( 0,1\right ) $$. Then, it moves back and forth in directions parallel to the $$x$$ and $$y$$ axes as shown in the figure, i.e., $$\left (0,0 \right ) \rightarrow \left (0,1 \right ) \rightarrow \left ( 1,1\right ) \rightarrow \left ( 1,0\right ) \rightarrow \left ( 2,0\right )\rightarrow \cdots $$. It moves one unit length per second. Therefore, at $$2016$$ seconds, the position of the particle is ___.
$$\left (8,44 \right ) $$
math
cb777310-fb3a-4d39-addd-ad3bb04288fb
As shown in the figure, $$D$$ is a point on the side $$BC$$ of $$\triangle ABC$$, and $$\angle 1=\angle 2$$, $$\angle 3=\angle 4$$, $$\angle BAC=63^{\circ}$$, then $$\angle DAC=$$ ___.
$$24$$
math
b7d25a03-b055-473f-929d-60890f37caea
As shown in the figure, $$AA_{1}$$ and $$BB_{1}$$ intersect at point $$O$$, $$AB∥A_{1}B_{1}$$, and $$AB=\dfrac{1}{2}A_{1}B_{1}$$. If the diameter of the circumcircle of $$\triangle AOB$$ is $$1$$, then the diameter of the circumcircle of $$\triangle A_{1}OB_{1}$$ is ___.
$$2$$
math
f99d14a8-1b4e-4e3c-b831-9e6ccecdffe2
As shown in the figure, there are 5 sets of data (x, y). After removing one set of data, the linear correlation of the remaining 4 sets of data can be maximized. Which set of data should be removed?
$$D(3,10)$$
math
538a04da-d419-42f6-9ea0-dbaa07aab062
The table below records the results of a player's free throws. As the number of attempts increases, the frequency of successful shots gradually stabilizes to ___. (Round to $$0.1$$)
$$0.5$$
math
faa18c3b-75ca-4db5-bbc0-62157cd5da3a
A region monitors the speed of vehicles on a certain road section, and 40 vehicles are selected for speed analysis, resulting in the frequency distribution histogram of speeds shown in the figure. According to the graph, the number of vehicles traveling at less than 70 km/h is:
16
math
67941629-6fab-442e-80d9-65acf5b813c7
In the figure, in parallelogram $ABCD$, the angle bisector $AE$ of $\angle DAB$ intersects $CD$ at $E$, $AB=5$, $BC=3$. Find the length of $EC$.
2
math
fc04a9bf-34da-4d14-9520-7160c52b41af
Integers are arranged in a regular pattern as shown in the figure. The last number in the 2nd row is $-4$, the last number in the 3rd row is 9, the last number in the 4th row is $-16$, and so on. What is the 21st number in the 21st row?
421
math
a51ea971-c732-4238-b67c-5f291c3e949d
In the figure, in $\vartriangle ABC$, $DE\text{//}BC$, AB=5, AC=3. If BD=AE, then the length of AD is.
$\frac{25}{8}$
math
32107ceb-c99e-429a-90cf-faa99470cc18
As shown in the figure, point E is on the extension of side BC of ΔABC. CD bisects ∠ACE. If ∠A = 70° and ∠DCA = 65°, then the measure of ∠B is.
60°
math
62387b2d-b8cf-4378-9ef2-71c6ce2ed004
As shown in the flowchart, if the input value of $x$ is $-5.5$, then the output result $c=$.
1
math
31aab6ac-0fa0-4cd6-8751-552901d96699
Given that the distance between places A and B is 10 kilometers, at 9:00 AM, person 甲 starts riding an electric bike from A to B, and at 9:10 AM, person 乙 starts driving from B to A. The relationship between the distance y (kilometers) from A and the time x (minutes) used by 甲 is shown in the figure below, then the time when 乙 arrives at A is.
9:20
math
d1bf96ea-c327-43e3-9b55-6c9508cd7676
As shown in the figure, in the Cartesian coordinate system, a perpendicular line is drawn from point $$A_{1}\left(0,-\dfrac{1}{3}\right)$$ to the $$y$$-axis, intersecting the line $$y=-x$$ at point $$B_{1}$$. Then, a perpendicular line is drawn from point $$B_{1}$$ to the line $$y=-x$$, intersecting the $$y$$-axis at point $$A_{2}$$. Next, a perpendicular line is drawn from point $$A_{2}$$ to the $$y$$-axis, intersecting the line $$y=-x$$ at point $$B_{2}$$, and so on. What are the coordinates of $$B_{6}$$?
$$\left(\dfrac{32}{3},-\dfrac{32}{3}\right)$$
math
8c349d34-1a8c-483e-8cf3-759298e831fb
The graph of the quadratic function $$y=ax^{2}+bx+c$$ is shown in the figure, with its axis of symmetry being the line $$x=1$$. If one of its intersections with the $$x$$-axis is $$A\left ( 3,0\right ) $$, then from the graph, the solution set of the inequality $$ax^{2}+bx+c < 0$$ is ___.
$$-1 < x < 3$$
math
7f2f01a4-7f62-4f0f-940c-72c411d1ae10
In the figure, in $$\triangle ABC$$, $$AB=BC$$, $$∠ABC=110^{\circ}$$, the perpendicular bisector $$DE$$ of $$AB$$ intersects $$AC$$ at point $$D$$, and $$BD$$ is connected, then $$∠ABD=$$ ___ degrees.
$$35$$
math
4f8e96e0-7d71-4a95-a959-e15a91119992
Given that the side length of rhombus ${{A}_{1}}{{B}_{1}}{{C}_{1}}{{D}_{1}}$ is $2$, $\angle {{A}_{1}}{{B}_{1}}{{C}_{1}}$=120°, and the diagonals ${{A}_{1}}{{C}_{1}},{{B}_{1}}{{D}_{1}}$ intersect at point $O$. Using point $O$ as the origin, and the lines $O{{A}_{1}},O{{B}_{1}}$ as the $x$-axis and $y$-axis respectively, a Cartesian coordinate system is established as shown in the figure. Rhombus ${{B}_{2}}{{C}_{1}}{{D}_{2}}{{A}_{1}}$ is constructed with ${{A}_{1}}{{C}_{1}}$ as the diagonal, similar to rhombus ${{A}_{1}}{{B}_{1}}{{C}_{1}}{{D}_{1}}$. Then, rhombus ${{A}_{2}}{{B}_{2}}{{C}_{2}}{{D}_{2}}$ is constructed with ${{B}_{2}}{{D}_{2}}$ as the diagonal, similar to rhombus ${{B}_{2}}{{C}_{1}}{{D}_{2}}{{A}_{1}}$. Next, rhombus ${{B}_{3}}{{C}_{2}}{{D}_{3}}{{A}_{2}}$ is constructed with ${{A}_{2}}{{C}_{2}}$ as the diagonal, similar to rhombus ${{A}_{2}}{{B}_{2}}{{C}_{2}}{{D}_{2}}$, and so on. Let the area of rhombus ${{A}_{1}}{{B}_{1}}{{C}_{1}}{{D}_{1}}$ be ${{S}_{1}}$, the area of rhombus ${{A}_{2}}{{B}_{2}}{{C}_{2}}{{D}_{2}}$ be ${{S}_{2}}$, ..., and the area of rhombus ${{A}_{n}}{{B}_{n}}{{C}_{n}}{{D}_{n}}$ be ${{S}_{n}}$. Then, ${{S}_{n}}=$.
$2\sqrt{3}\times {{9}^{n-1}}$
math
e15190d0-d585-44e0-833e-f762fe5f50aa
As shown in the figure, there is a right-angled triangular piece of paper, with the two perpendicular sides AC=6cm and BC=8cm. Now, the right-angled side is folded along the line AD, so that it falls on the hypotenuse AB and coincides with AE. What is the length of CD?
3cm
math
a14bbb0f-dbbf-43bd-b946-f485034ce5e1
As shown in the figure, the line y=1 passes through point A and intersects the y-axis at point B, with OA=2. There is a point P on line AB. If triangle POA is an isosceles triangle with OA as a leg, then the coordinates of point P are.
$(-\sqrt{3},1);(-2+\sqrt{3},1);(2+\sqrt{3},1)$
math
8d461976-01a8-4375-86c2-bd8ba6581fcb
In rectangle $\text{ABCD}$, $\text{M}$ is the midpoint of side $\text{AD}$, $\text{P}$ is a point on side $\text{BC}$, $\text{PE}\bot \text{MC}$, $\text{PF}\bot \text{MB}$. When $\text{AB}$ and $\text{BC}$ satisfy certain conditions, quadrilateral $\text{PEMF}$ is a rectangle.
$\text{AB}=\frac{1}{2}\text{BC}$
math
cee55e9b-6f1a-4eb7-8e8a-4d7fc594ca8a
As shown in the figure, in $\Delta ABC$, $BF$ bisects $\angle ABC$, $AG \perp BF$, with the foot of the perpendicular at point $D$, intersecting $BC$ at point $G$. $E$ is the midpoint of $AC$, and $DE$ is connected. Given that $DE = 2.5cm$ and $AB = 4cm$, the length of $BC$ is $cm$.
6.5
math
a1b67524-cb35-4654-831c-7587e305d837
In the figure, in rectangle ABCD, DE is perpendicular to AC at point F and intersects side BC at point E. Given AB = 6, AD = 8, find the length of CE.
4.5
math
88b856b9-eef3-4bc0-af20-c5a577039c90
As shown in the figure, line segment AD intersects with BC at point O, AB∥CD. If AB:CD = 2:3, and the area of △ABO is 2, then the area of △CDO is
4.5
math
15677376-ad9d-4161-81fa-0807ac81978c
Execute the algorithm flowchart shown in the figure. If the input value of $x$ is 2, then the output value of $n$ is.
2
math
c03f9481-4e14-48cf-a0b7-b300fe93c51a
The graph of the linear function $y=ax+b$ is shown in the figure. The solution set of the inequality $ax+b > 2$ is.
$x > 2$
math
6208a1e0-1ef9-428c-bedf-577711c05c01
As shown in the figure, it is known that the graphs of the functions y=kx+b and y=$\frac{1}{2}$x-2 intersect at point P. According to the graph, the solution to the inequality system kx+b<$\frac{1}{2}$x-2<0 is.
2<x<4
math
b8d49160-1526-4948-a6da-c54ce4882fc6
As shown in the figure, A and B are two grid points on a grid composed of small squares with side length 1. Place point C arbitrarily on any grid point (excluding points A and B). The probability that a triangle can be drawn with points A, B, and C as vertices is.
$\frac{31}{34}$
math
3597395d-1ca9-46ae-ab2a-70fc2b8f0564
As shown in the figure, in the right trapezoid $$ABCD$$, $$DC \parallel AB$$, $$CB \perp AB$$, $$AB=AD=a$$, $$CD=\dfrac{a}{2}$$, points $$E$$ and $$F$$ are the midpoints of segments $$AB$$ and $$AD$$, respectively. Then $$EF=$$ ___.
$$\dfrac{a}{2}$$
math
7d90d0b8-8473-482c-bbd3-bc7707f84b50
A middle school randomly surveyed 50 students to understand their physical exercise time at school during the week. The results are shown in the following table: What is the average physical exercise time for these 50 students at school this week? ___ hours.
6.4
math
ee149518-edcc-47a7-817b-66192241f058
As shown in the figure, given that line $$AB \parallel CD$$, $$\angle C=125^{\circ}$$, and $$\angle A=45^{\circ}$$, then $$\angle E=$$ ___.
$$80^{\circ}$$
math
9ca92fcf-d93e-4a34-84fd-dc3176f8e7fc
Referring to the flowchart shown in the figure, if $$a=5^{0.6}$$, $$b=0.6^{5}$$, $$c=\log_{0.5}5$$, then the number output is among $$a$$, $$b$$, and $$c$$, which is ___.
$$a$$
math
ecdd1c47-24ce-4d55-b95c-ae86d10fc1cf
As shown in the figure, the area of the large square is $$13$$, and four congruent right triangles form a smaller square. The length of the shorter leg of the right triangle is $$2$$. If a dart is thrown at the large square, what is the probability that the dart lands inside the smaller square?
$$\dfrac{1}{13}$$
math
b1e4e85f-48dd-44af-beff-dea52761c510
Let the probability distribution of a random variable be as shown in the table below, and given that $$E(\xi) = 1.6$$, then $$a - b =$$ ___.
$$-0.2$$
math
e24f1f1f-63e9-4e39-bef5-8efbe5d8bcef
A daily commodity is classified into five quality levels according to industry standards, with the quality coefficients $$X$$ being $$1$$, $$2$$, $$3$$, $$4$$, and $$5$$ respectively. Now, $$200$$ items are randomly selected from a batch of this commodity, and the frequency $$f$$ of their quality coefficients is recorded in the following distribution table: Among the $$200$$ selected items, the number of items with a quality coefficient $$X=1$$ is ___.
$$20$$
math
bfc5d0eb-c650-49cd-8588-79914b0738ac
As shown in the figure, in a semicircle with a radius of $$1$$, a square $$ABCD$$ with a side length of $$\dfrac{1}{2}$$ is placed. If a point is randomly thrown into the semicircle, the probability that the point lands inside the square is ___.
$$\dfrac{1}{2\pi }$$
math
ce2a955a-bef0-4479-b3f2-ca3ee478040b
A junior high school's ninth grade has the following table on the health bulletin board. What is the average score of Class (2) for the week?
$$9.7$$
math
be863258-1d8d-4dc9-8d7f-8c06908c8084
As shown in the figure, the pattern is arranged according to a certain rule. Following this rule, in the 1st to the 2012th pattern, the total number of '♣' is ___.
503
math
131acc2f-0983-46eb-9ff3-2ac7b8ceae58
In the flowchart shown, if the input $$x \in [-1,4]$$, then the probability that the output $$y \in (0,1]$$ is ___.
$$\dfrac{1}{5}$$
math
6dcb075c-f270-4ef4-bcc8-b2ef2f41b512
As shown in the figure, lines $$m \parallel n$$, and $$\triangle ABC$$ is an isosceles right triangle with $$\angle BAC = 90^{\circ}$$, then $$\angle 1 =$$ ___ degrees.
$$45$$
math
129c0f1b-27e7-4db0-b11f-e393d50d1b25
As shown in the figure, there is a movable frame in the shape of a parallelogram, with the diagonals being two rubber bands. If the shape of the frame is changed, then the angle $$∠\alpha$$ also changes, and the lengths of the two diagonals also vary. When $$∠\alpha$$ is ___, the lengths of the two diagonals are equal.
$$90^{\circ}$$
math
b522a987-e20d-4665-b909-fe9ca009be53
The figure below is a flowchart for calculating the value of $$1^{2}+2^{2}+3^{2}+\cdots +100^{2}$$, then the positive integer $$n=$$ ___.
$$100$$
math
a11b7916-733f-4eda-8e39-c2323af72f79
Given that the front view and side view of a certain geometric body are as shown in the figure, among the following 5 figures: the number of figures that can be used as the top view of the geometric body is ___
$$4$$
math
9726e46b-3ae7-462a-ba23-79ecc1476172
As shown in the figure, line $$AB$$ and line $$OC$$ intersect at point $$O$$, $$∠AOC=100^{\circ}$$, then $$∠1=$$ ___ degrees.
$$80$$
math
087378ac-83cf-4999-8596-d0c85b40b2ec
As shown in the figure, in the Cartesian coordinate system, circle $$⊙A$$ passes through point $$O$$, and intersects the $$x$$-axis and $$y$$-axis at points $$B$$ and $$C$$ respectively. Given that $$B\left ( 12,0\right ) $$ and $$C\left ( 0,5\right )$$, the radius of $$⊙A$$ is ___.
$$\dfrac{13}{2}$$
math
64723254-89e9-4c00-b03b-85a4b12b1165
As shown in the figure, line $$AB \parallel CD$$, line $$EF$$ intersects $$AB$$ and $$CD$$ at points $$E$$ and $$F$$ respectively, $$FP \perp EF$$ at point $$F$$, and intersects the bisector of $$\angle BEF$$ at point $$P$$. If $$\angle 1=20^{ \circ }$$, then the measure of $$\angle P$$ is ___.
$$55^{\circ}$$
math
061a5b7c-94a6-4b4e-8d92-460cd78bb113
Let the height of a frustum of a cone be $$3$$, and its axial section is shown in the figure. The angle between the generatrix $$AA_{1}$$ and the diameter $$AB$$ of the bottom circle is $$60^{\circ}$$, and one of the diagonals in the axial section is perpendicular to the side. What is the volume of the frustum?
$$21 \pi$$
math
3ed81d55-d087-4ad2-a3c3-b3df5d8f9929
The three views of a triangular pyramid are shown in the figure. Its front view, side view, and top view are all right-angled triangles, with areas of $$1$$, $$2$$, and $$4$$, respectively. The volume of this geometric body is ___.
$$\dfrac{4}{3}$$
math
918df50e-e3ef-45f6-b34f-91c480e0c465
The figure shows the three views of a geometric solid. The volume of this solid is ___. (The result should be in terms of $$π$$)
$$250\pi$$
math
5330815c-bf04-48ce-9dd1-029134b9f68b
As shown in the figure, in the circular spinner, the central angles of the three sectors $$A$$, $$B$$, and $$C$$ are $$150^{\circ}$$, $$120^{\circ}$$, and $$90^{\circ}$$, respectively. After spinning the spinner, the probability of the pointer stopping at any position is the same (if the pointer stops on the boundary line, the spinner is spun again). What is the probability that the pointer stops in region $$B$$ after one spin?
$$\dfrac{1}{3}$$
math
4e347e89-aa66-409b-8d33-795fb0df4b9f
As shown in the figure, the distances from two lighthouses $$A$$ and $$B$$ to the marine observation station $$C$$ are both $$a\,km$$. Lighthouse $$A$$ is located at a bearing of $$20^{\circ}$$ north of east from station $$C$$, and lighthouse $$B$$ is located at a bearing of $$40^{\circ}$$ south of east from station $$C$$. The distance between lighthouses $$A$$ and $$B$$ is ___ $$km$$.
$$\sqrt{3}a$$
math
cbbae228-5b58-4cdc-9a1b-4d1659dda48f
As shown in the figure, it is known that all the edges of the triangular prism $$ABC{-}A_{1}B_{1}C_{1}$$ are $$1$$, and $$AA_{1} \perp $$ the base $$ABC$$. What is the volume of the tetrahedron $$B_{1}-ABC_{1}$$?
$$\dfrac{\sqrt{3}}{12}$$
math
52538d7a-f24f-4b3a-84ac-f6f038f46b4d
The stem-and-leaf plot of a class's Chinese scores is shown in the figure. The excellence rate (90 points and above) is ___, and the lowest score is ___.
4% 51
math
270c879c-f33f-4e75-9c88-ced5ca17b992
As shown in the figure, $$AB$$ is the diameter of $$\odot O$$, $$C$$ is a point on $$\odot O$$, $$CD \perp AB$$, with the foot of the perpendicular at $$D$$, $$F$$ is the midpoint of the arc $$\overset{\frown} {AC}$$, $$OF$$ intersects $$AC$$ at point $$E$$, $$AC=8$$, $$EF=2$$. The length of $$AD$$ is ___.
$$\dfrac{32}{5}$$
math
132ac66c-6ab4-48ba-b24e-8b24419b1164
As shown in the figure, a beam of parallel sunlight shines on a regular pentagon, then $$ \angle 1=$$___$$^{\circ}$$.
$$30$$
math
986dede4-6ead-45ec-827c-f3feafea1a54
Use small cubes to build a geometric shape such that the views from the right side and the top are the two shapes shown below. The minimum number of small cubes needed to build such a geometric shape is $$x$$, and the maximum number of small cubes needed is $$y$$. Then $$x+y=$$ ______.
12
math
2d0dc165-a5d1-4f84-ad45-a6d1b15c03e5
The distribution of the random variable $$\xi$$ is as follows: The variance of the random variable $$\xi$$, $$D(\xi)$$, is ______.
$$1$$
math
c72aba52-2348-441f-b200-b956dc0c49ec
As shown in the figure, in the equilateral triangle $$ABC$$, $$D$$ and $$E$$ are on $$AC$$ and $$AB$$ respectively, and $$\dfrac{AD}{AC}=\dfrac{1}{3}$$, $$AE=BE$$. Then, $$ \triangle AED\sim $$___.
$$\triangle CBD$$
math
76dfa7cd-e19f-41f9-b7f9-e484798796fb
As shown in the figure, in the right trapezoid $$ABCD$$, $$AB \parallel CD$$, $$\angle DAB=90^{\circ}$$, $$AD=AB=4$$, $$CD=1$$. A moving point $$P$$ is on the side $$BC$$, and satisfies $$\overrightarrow{AP}=m\overrightarrow{AB}+n\overrightarrow{AD}$$ ($$m$$, $$n$$ are both positive real numbers). Then the minimum value of $$\dfrac{1}{m}+\dfrac{1}{n}$$ is ___.
$$\dfrac{7+4\sqrt{3}}{4}$$
math
6c3d50cb-b5cb-419f-b840-503957daadfe
As shown in the figure, point E is on the extension of side BC of square ABCD, and CE = AC. Connect AE. Then, ∠ACE = ______ degrees.
135
math
b491d833-5a5b-4249-95b0-93023ada5bfb
Draw a perpendicular from the pole to the line $$l$$, and the polar coordinates of the foot of the perpendicular are $$\left(3,\dfrac{2 \pi }{3}\right)$$. Then the polar equation of $$l$$ is ___.
$$ \rho \cos \left(\dfrac{2 \pi }{3}- \theta \right)=3$$
math
b705a75a-5890-430b-bbf0-3268515d2fb4
As shown in the figure, the diagonals of $$\square ABCD$$ intersect at point $$O$$. Please add one condition: ___ (fill in only one), to make $$ABCD$$ a rectangle.
$$AC=BD$$
math
4e18a787-d35c-44a2-9e82-1f9b1665204c
As shown in the figure, in the right triangle $$ABC$$, $$D$$ is the midpoint of the hypotenuse $$AB$$, $$AC=6cm$$, $$BC=8cm$$, $$EC\bot$$ plane $$ABC$$, $$EC=12cm$$. Then, $$ED=$$ ___ $$cm$$.
$$13$$
math
4dc640d5-6c87-48e8-9bad-9d88261a4853
As shown in the figure, a flea starts from point M, first climbs up 2 units, then moves left 3 units to reach point P, and then jumps to the point P1, which is the reflection of point P over the x-axis. What are the coordinates of point P1?
(-3, -3)
math
9e5510c7-c00e-409e-be3a-7b08eaed8109
Given that the side length of square $ABCD$ is 6, points $E$ and $F$ are on $AD$ and $DC$ respectively, with $AE=DF=2$. $BE$ intersects $AF$ at point $G$, and point $H$ is the midpoint of $BF$. Connecting $GH$, the length of $GH$ is.
$\sqrt{13}$
math
15ce77fc-9e16-41d1-b0b6-85e22942d847
The positions of the rational numbers $a, b, c$ on the number line are shown in the figure: Then the simplified result of the algebraic expression $\left| a+c \right|-2\left| a-b \right|+\left| b-c \right|$ is.
$a-3b$
math
ad7df31a-7525-467a-9180-52123ad4acfb
As shown in the figure, above the x-axis, a line parallel to the x-axis intersects the graphs of the inverse proportion functions y = $\frac{k_1}{x}$ and y = $\frac{k_2}{x}$ at points A and B, respectively. Connecting OA and OB, if the area of △AOB is 6, then $k_1 - k_2$ = .
-12
math
03be736f-0715-450f-98d0-7035995a6229
As shown in the figure, ABCD—A$_{1}$B$_{1}$C$_{1}$D$_{1}$ is a cube with edge length a. The angle formed by AB$_{1}$ and the plane D$_{1}$B$_{1}$BD is =.
${{30}^{\circ }}$
math
99018e15-fca6-4ee9-b689-61940b105128
In the right triangle ABC, ∠BAC = 90°, AB = 3, AC = 4, and AD is perpendicular to BC at point D. Find the length of AD.
$\frac{12}{5}$
math
bb66eda6-c9f6-4917-9ae2-347b50ec0b83
As shown in the figure, the radius of the sector is 3, and the central angle θ is 120°. Using this sector to form the lateral surface of a cone, the radius of the base of the cone is.
1
math
3dcade39-0749-4369-9efb-7d20c0218545
As shown in the figure, the side length of square ABCD is 4, the diagonals AC and BD intersect at point O, and a semicircle is drawn with BC as the diameter. The area of the shaded region in the figure is.
12 - 2π
math
769bccba-997f-4ab6-9dd1-b6605ad98ea2
A component is composed of four electronic elements connected in the manner shown in the diagram. The component operates normally if element 1 or element 2 is functioning, and element 3 or element 4 is functioning. The lifespans (in hours) of the four electronic elements all follow a normal distribution $N(1000,{{50}^{2}})$, and the functioning of each element is independent of the others. What is the probability that the component's lifespan exceeds 1000 hours?
$\frac{9}{16}$
math
857d1256-e2ba-4ee8-97b6-3a998ee5967c
As shown in the figure, there are nine cards printed with different car logos (except for the patterns, all other aspects of the cards are the same). Now, the patterned side is placed face down, and one card is drawn at random. The probability of drawing a card with a centrally symmetric car logo is.
$\frac{1}{9}$
math
1bfaa1ff-5d4d-4e8d-b9d7-1c807cd56ee8
Given the line y = kx + b (k > 0, b > 0) intersects the x-axis and y-axis at points A and B, respectively, and intersects the hyperbola y = 16/x (x > 0) at point C in the first quadrant. If BC = 2AB, then the area of triangle AOB is:
4/3
math
1d726f8d-61f8-46a7-b031-fcca4d3dd041
As shown in the figure, in the right triangle ABC, ∠C=90°, AB=5, AC=4. Semicircles are drawn with the three sides of the right triangle ABC as diameters. The area of the shaded region is.
6
math
5c51a86d-84d5-4d4e-b97e-93ef2c177e39
As shown in the figure, the feasible region of the objective function $u=ax-y$ is the quadrilateral $OACB$ (including the boundaries). If point $C\left( \frac{2}{3},\frac{4}{5} \right)$ is the unique optimal point of this objective function, then the range of values for $a$ is.
$\left( -\frac{12}{5},-\frac{3}{10} \right)$
math
07257871-fcb6-411e-b1a0-b62de9e5f703
In the figure, in $\vartriangle ABC$, $AC=AD=BD$, and $\angle DAC=80{}^\circ$. What is the measure of $\angle B$?
$25{}^\circ$
math
93de362d-665f-4914-9882-b2d9ae3094fc
As shown in the figure, all quadrilaterals are squares, and all triangles are right triangles. If the sum of the areas of squares A, B, and C is 9, then the side length of square D is.
3
math
6eb025d9-5a53-4ba1-831a-e5781c7cef80
Given the function $y=A\sin (\omega x+\varphi )(A > 0,\omega > 0,|\varphi | < \pi )$ with the graph shown below, the formula for this function is:
$y=2\sin \left( 2x+\frac{\pi }{6} \right)$
math
716bce19-1769-4f2b-8b9d-2d4c716cae2d
As shown in the figure (units: cm), express the area of the shaded part in the triangular ruler in cm$^{2}$.
$\frac{1}{2}ab-\pi {{r}^{2}}$
math
51666a19-35ce-417b-ac84-dea97c37a367
The results of a germination test for a certain type of rapeseed under the same conditions are shown in the table below: The probability of this type of rapeseed germinating is ___ (result rounded to $$0.01$$).
$$0.95$$
math
f5252fd8-f715-4942-8dae-4f52ff4d1c18
As shown in the figure, in the rectangular coordinate system $$xOy$$, the vertices of triangle $$ABC$$ are $$A(0,a)$$, $$B(b,0)$$, and $$C(c,0)$$, and point $$P(0,p)$$ is a point on the line segment $$AO$$ (excluding the endpoints). Here, $$a$$, $$b$$, $$c$$, and $$p$$ are non-zero real numbers. The lines $$BP$$ and $$CP$$ intersect the sides $$AC$$ and $$AB$$ at points $$E$$ and $$F$$, respectively. A student has correctly derived the equation of line $$OE$$ as: $$\left ( \dfrac{1}{c}-\dfrac{1}{b}\right )x-\left ( \dfrac{1}{p}-\dfrac{1}{a}\right )y=0$$. Please complete the equation of line $$OF$$: (___)$$x-$$$$\left(\dfrac{1}{p}-\dfrac{1}{a}\right)y=0$$.
$$\dfrac{1}{b}-\dfrac{1}{c}$$
math
f2504ae3-e320-47a7-a84c-bdea65915e48
The curve corresponding to the equation $$y=-\sqrt{4-x^{2}}$$ is ___ (fill in the number).
1
math
922ddf47-d6fc-4b21-addf-49dec05ac965
Following the operation steps shown in the figure, if the input value of $$x$$ is $$1$$, then the output value is ___.
$$11$$
math
48bd00c6-116a-464f-a33d-184748046f38
Point $$P(3a,a)$$ is an intersection point of the graph of the inverse proportion function $$y=\dfrac{k}{x}(k>0)$$ and circle $$⊙O$$. The area of the shaded part in the figure is $$10π$$. What is the formula for the inverse proportion function?
$$y=\dfrac{12}{x}$$
math
fa57dd98-7b79-4914-a18c-1da1739da302
Given that the solution to the equation ax+by=4 is , please write an equation containing a and b ______.
2a+b=4
math
c2dce387-741b-43e1-bf03-38c3e801d55c
Given the function $$f(x)=\begin{cases} 4x, &0< x \leqslant 5, \\ 20, &5 < x \leqslant 9, \\ 56-4x, &9< x \leqslant 14, \end{cases}$$ find $$f(a) (a \in (0,14])$$ in the algorithm, a selection structure is needed, where the shape of the decision box is ___ (fill in the number).
4
math
0ab786dd-aba0-405d-b06a-8fc3b74cc7c4
On the 90th anniversary of the founding of the Communist Party of China, the County Education Bureau held a 'Red Songs Resound in China' activity. A 'Red Songs' singing competition was held in June. The organizing committee stipulates: any participant's score x satisfies: 60 ≤ x < 100. After the competition, the scores of all participants were organized as shown in the following table: According to the information provided in the table, n = ___.
0.25
math
5c3a8d6c-e254-419c-9ae6-0fb537a26e0c
The perspective view of a geometric solid is shown in the figure. Among the following four top views, which one is correct?
2
math
6c70e63b-43ef-4133-9431-581c7bf1111f
As shown in the figure, $$PD$$ is perpendicular to the plane of the square $$ABCD$$. Given that $$AB=2$$, $$E$$ is the midpoint of $$PB$$, and $$\cos〈\overrightarrow{DP},\overrightarrow{AE}〉=\dfrac{\sqrt{3}}{3}$$, if a spatial rectangular coordinate system is established with the lines containing $$DA$$, $$DC$$, and $$DP$$ as the $$x$$-axis, $$y$$-axis, and $$z$$-axis respectively, then the coordinates of point $$E$$ are ___.
$$(1,1,1)$$
math
8e3a55e0-4a4b-476b-8daa-22fd1c57d408
As shown in the figure, in $\Delta ABC$, $\angle B=40{}^\circ $, $\angle C=28{}^\circ $, point $D$ is on the extension of $BA$. What is the measure of $\angle CAD$?
68°
math
8d2e9b25-4383-4a8c-8051-229f672be130
If the front view of a triangular prism with a regular triangular base is shown in the figure below, then its surface area is.
$6+2\sqrt{3}$
math
f7afdc83-fc56-46cf-8612-dc2747f29cf0
The three views of a geometric body are shown in the figure, and all three triangles are right-angled triangles. What is the maximum value of xy?
64
math
c53d2068-0a9a-42c6-8e32-037bfabe27f7
In the parallelogram $ABCD$, $\overrightarrow{AB}=\overrightarrow{a}$, $\overrightarrow{AD}=\overrightarrow{b}$, point $O$ is the intersection of diagonals $AC$ and $BD$, and point $E$ is on side $CD$ such that $DE=2EC$. Then $\overrightarrow{OE}=$ (express using $\overrightarrow{a}$ and $\overrightarrow{b}$).
$\frac{1}{2}\overrightarrow{b}+\frac{1}{6}\overrightarrow{a}$
math
64b0f1e1-e3c4-469e-8f65-1d1c99233378
To promote green travel in the city, the Little Blue Bike company plans to build a shared bike parking point E along the AB section of the Shiwu Port riverbank. There are two squares C and D nearby (as shown in the figure), with CA perpendicular to AB at A, and DB perpendicular to AB at B. AB = 4 km, CA = 2 km, and DB = 1 km. At what distance from point A should the parking point E be built so that its distance to both squares is equal?
$\frac{13}{8}$
math
90d0b5e7-718e-4813-989c-5c410419baaf
As shown in the figure, in parallelogram $ABCD$, $AB=2AD=2$, $\angle BAD=60{}^\circ $, and $E$ is the midpoint of $DC$. The cosine of the angle between vector $\overrightarrow{AC}$ and $\overrightarrow{EB}$ is equal to.
$\frac{\sqrt{7}}{14}$
math
57877655-362d-4ebf-a684-434b8f5202d6
As shown in the figure, there is an isosceles triangle paper with a base angle of $35^\circ$. Now, it is cut along a line perpendicular to the base through a point on the base, dividing it into a triangle and a quadrilateral. What is the degree measure of the largest angle in the quadrilateral?
125
math