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  C3 Mixed Exercise 7F Q9 watch
  
  1. Hi,
  
  I was wondering if anybody could help me, I am stuck on C3 Mixed Exercise 7F, Question 9 c and d.
  
  C - solve
  sin(θ+40°) + sin(θ+50°) = 0 , 0 ≤ θ ≤ 360°
  
  D - solve
  sin² θ/2 = 2sinθ ,0 ≤ θ ≤ 360°
  
  Any help would be appreciated as Physics and Math Tutors Solution jump around and don't really explain anything, which is annoying...
  
  Thanks!
  2. (Original post by BenRichi_)
  Hi,
  
  I was wondering if anybody could help me, I am stuck on C3 Mixed Exercise 7F, Question 9 c and d.
  
  C - solve
  sin(θ+40°) + sin(θ+50°) = 0 , 0 ≤ θ ≤ 360°
  
  D - solve
  sin² θ/2 = 2sinθ ,0 ≤ θ ≤ 360°
  
  Any help would be appreciated as Physics and Math Tutors Solution jump around and don't really explain anything, which is annoying...
  
  Thanks!
  3. sin(θ) = cos(90-θ)
  cos(θ) = sin(90 - θ)
  4. (Original post by TeeEm)
  Well for C I started by using the addition formulae to expand, but was just left with nothing. And nothing for D
  5. sin(x+50) = cos(x+40)
  So -tan(x+40) = 0
  6. (Original post by NotNotBatman)
  sin(θ) = cos(90-θ)
  cos(θ) = sin(90 - θ)
  Where does this come from?
  7. (Original post by BenRichi_)
  Well for C I started by using the addition formulae to expand, but was just left with nothing. And nothing for D
  does post 3 help?
  8. (Original post by TeeEm)
  does post 3 help?
  Well I understand how I would use it, but don't understand where that is from, I have never seen this before?
  9. (Original post by TeeEm)
  does post 3 help?
  Youre trying too much
  10. (Original post by BenRichi_)
  Where does this come from?
  It's taught in c2. Draw a right angled triangle with an angle marked x, so the other angle will have to be 90-x and you'll see that it works.
  
  or consider the cosine and sine graphs.
  11. (Original post by BenRichi_)
  Well I understand how I would use it, but don't understand where that is from, I have never seen this before?
  standard result taught at C2
  12. (Original post by GeologyMaths)
  Youre trying too much
  I don't think that your solution works, or makes sense...
  13. (Original post by BenRichi_)
  Well I understand how I would use it, but don't understand where that is from, I have never seen this before?
  cos(x) = sin(90-x)
  cos(x) = sin90cosx - sinxcos90
  cos(x) = cos(x) - 0
  14. (Original post by BenRichi_)
  Hi,
  
  I was wondering if anybody could help me, I am stuck on C3 Mixed Exercise 7F, Question 9 c and d.
  
  C - solve
  sin(θ+40°) + sin(θ+50°) = 0 , 0 ≤ θ ≤ 360°
  
  D - solve
  sin² θ/2 = 2sinθ ,0 ≤ θ ≤ 360°
  
  Any help would be appreciated as Physics and Math Tutors Solution jump around and don't really explain anything, which is annoying...
  
  Thanks!
  Have u come across the factor formula? if not it is
  sinp+ sinq== 2sin(p+q/2)cos(p-q/2).... with p as 40° and q as 50°. Sub in values
  and you should come to 2sin(θ+45)=0 and cos(-5)=0 where cos(-5) is invalid therefore solve 2sin(θ+45)=0................... ...ok and tell me what you get
  15. (Original post by raman_17)
  Have u come across the factor formula? if not it is
  sinp+ sinq== 2sin(p+q/2)cos(p-q/2).... with p as 40° and q as 50°. Sub in values
  and you should come to 2sin(θ+45)=0 and cos(-5)=0 where cos(-5) is invalid therefore solve 2sin(θ+45)=0................... ...ok and tell me what you get
  Thank you very much raman, I was just looking through the C3 book and found this, its the best solution and gives the correct answer!
  16. (Original post by BenRichi_)
  Thank you very much raman, I was just looking through the C3 book and found this, its the best solution and gives the correct answer!
  no worries
  17. (Original post by BenRichi_)
  Hi,
  
  I was wondering if anybody could help me, I am stuck on C3 Mixed Exercise 7F, Question 9 c and d.
  
  C - solve
  sin(θ+40°) + sin(θ+50°) = 0 , 0 ≤ θ ≤ 360°
  
  D - solve
  sin² θ/2 = 2sinθ ,0 ≤ θ ≤ 360°
  
  Any help would be appreciated as Physics and Math Tutors Solution jump around and don't really explain anything, which is annoying...
  
  Thanks!
  sin(x)=2sin(x/2)cos(x/2)
  18. (Original post by BenRichi_)
  I don't think that your solution works, or makes sense...
  this person has been trolling the maths forum today.
  19. (Original post by the bear)
  this person has been trolling the maths forum today.
  how?
  
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explanation: The document is a forum post from a student seeking help with specific math problems from a C3 Mixed Exercise. The student is stuck on questions C and D, which involve solving trigonometric equations. The post includes the questions and mentions the student's frustration with the provided solutions. Multiple users respond with hints and suggestions to solve the problems.
distilabel_metadata.content: Evaluate the user given text extract and determine if it contains a math question and optionally and answer to this question.
  
  Output rules:
  
  1. Briefly describe the document and mention if it contains a question or a question and answer.
  2. Finalize the output with: Label: no-question,question,question-and-answer,multiple-question,multiple-question-and-answer
distilabel_metadata.role: system
distilabel_metadata.content: x Turn on thread page Beta
   You are Here: Home >< Maths
  
  C3 Mixed Exercise 7F Q9 watch
  
  1. Hi,
  
  I was wondering if anybody could help me, I am stuck on C3 Mixed Exercise 7F, Question 9 c and d.
  
  C - solve
  sin(θ+40°) + sin(θ+50°) = 0 , 0 ≤ θ ≤ 360°
  
  D - solve
  sin² θ/2 = 2sinθ ,0 ≤ θ ≤ 360°
  
  Any help would be appreciated as Physics and Math Tutors Solution jump around and don't really explain anything, which is annoying...
  
  Thanks!
  2. (Original post by BenRichi_)
  Hi,
  
  I was wondering if anybody could help me, I am stuck on C3 Mixed Exercise 7F, Question 9 c and d.
  
  C - solve
  sin(θ+40°) + sin(θ+50°) = 0 , 0 ≤ θ ≤ 360°
  
  D - solve
  sin² θ/2 = 2sinθ ,0 ≤ θ ≤ 360°
  
  Any help would be appreciated as Physics and Math Tutors Solution jump around and don't really explain anything, which is annoying...
  
  Thanks!
  3. sin(θ) = cos(90-θ)
  cos(θ) = sin(90 - θ)
  4. (Original post by TeeEm)
  Well for C I started by using the addition formulae to expand, but was just left with nothing. And nothing for D
  5. sin(x+50) = cos(x+40)
  So -tan(x+40) = 0
  6. (Original post by NotNotBatman)
  sin(θ) = cos(90-θ)
  cos(θ) = sin(90 - θ)
  Where does this come from?
  7. (Original post by BenRichi_)
  Well for C I started by using the addition formulae to expand, but was just left with nothing. And nothing for D
  does post 3 help?
  8. (Original post by TeeEm)
  does post 3 help?
  Well I understand how I would use it, but don't understand where that is from, I have never seen this before?
  9. (Original post by TeeEm)
  does post 3 help?
  Youre trying too much
  10. (Original post by BenRichi_)
  Where does this come from?
  It's taught in c2. Draw a right angled triangle with an angle marked x, so the other angle will have to be 90-x and you'll see that it works.
  
  or consider the cosine and sine graphs.
  11. (Original post by BenRichi_)
  Well I understand how I would use it, but don't understand where that is from, I have never seen this before?
  standard result taught at C2
  12. (Original post by GeologyMaths)
  Youre trying too much
  I don't think that your solution works, or makes sense...
  13. (Original post by BenRichi_)
  Well I understand how I would use it, but don't understand where that is from, I have never seen this before?
  cos(x) = sin(90-x)
  cos(x) = sin90cosx - sinxcos90
  cos(x) = cos(x) - 0
  14. (Original post by BenRichi_)
  Hi,
  
  I was wondering if anybody could help me, I am stuck on C3 Mixed Exercise 7F, Question 9 c and d.
  
  C - solve
  sin(θ+40°) + sin(θ+50°) = 0 , 0 ≤ θ ≤ 360°
  
  D - solve
  sin² θ/2 = 2sinθ ,0 ≤ θ ≤ 360°
  
  Any help would be appreciated as Physics and Math Tutors Solution jump around and don't really explain anything, which is annoying...
  
  Thanks!
  Have u come across the factor formula? if not it is
  sinp+ sinq== 2sin(p+q/2)cos(p-q/2).... with p as 40° and q as 50°. Sub in values
  and you should come to 2sin(θ+45)=0 and cos(-5)=0 where cos(-5) is invalid therefore solve 2sin(θ+45)=0................... ...ok and tell me what you get
  15. (Original post by raman_17)
  Have u come across the factor formula? if not it is
  sinp+ sinq== 2sin(p+q/2)cos(p-q/2).... with p as 40° and q as 50°. Sub in values
  and you should come to 2sin(θ+45)=0 and cos(-5)=0 where cos(-5) is invalid therefore solve 2sin(θ+45)=0................... ...ok and tell me what you get
  Thank you very much raman, I was just looking through the C3 book and found this, its the best solution and gives the correct answer!
  16. (Original post by BenRichi_)
  Thank you very much raman, I was just looking through the C3 book and found this, its the best solution and gives the correct answer!
  no worries
  17. (Original post by BenRichi_)
  Hi,
  
  I was wondering if anybody could help me, I am stuck on C3 Mixed Exercise 7F, Question 9 c and d.
  
  C - solve
  sin(θ+40°) + sin(θ+50°) = 0 , 0 ≤ θ ≤ 360°
  
  D - solve
  sin² θ/2 = 2sinθ ,0 ≤ θ ≤ 360°
  
  Any help would be appreciated as Physics and Math Tutors Solution jump around and don't really explain anything, which is annoying...
  
  Thanks!
  sin(x)=2sin(x/2)cos(x/2)
  18. (Original post by BenRichi_)
  I don't think that your solution works, or makes sense...
  this person has been trolling the maths forum today.
  19. (Original post by the bear)
  this person has been trolling the maths forum today.
  how?
  
  TSR Support Team
  
  We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.
  
  This forum is supported by:
  Updated: January 30, 2016
  Today on TSR
  
  Been caught plagiarising...
  
  ...for the 2nd time this year
  
  Mum says she'll curse me if I don't go to uni
  
  Discussions on TSR
  
  • Latest
  Poll
  Useful resources
  
  Maths Forum posting guidelines
  
  Not sure where to post? Read the updated guidelines here
  
  How to use LaTex
  
  Writing equations the easy way
  
  Study habits of A* students
  
  Top tips from students who have already aced their exams
  
  Chat with other maths applicants
  
  Groups associated with this forum:
  
  View associated groups
  Discussions on TSR
  
  • Latest
  
  The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.
  
  Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE
distilabel_metadata.role: user
distilabel_metadata.raw_output_q_a_detector_0: The document is a forum post from a student seeking help with specific math problems from a C3 Mixed Exercise. The student is stuck on questions C and D, which involve solving trigonometric equations. The post includes the questions and mentions the student's frustration with the provided solutions. Multiple users respond with hints and suggestions to solve the problems.
  
  Label: question-and-answer