If 4f^4 − 41f^2 + 100 = 0, then what is the sum of the two greatest possible values of f ?
Select
A) 4
B) 9/2
C) 7
D) 41/4
E) 25
just forget about the value of f^4 for the moment and let f^2= X. (its better to work with power of 2 than 4)   now we have equation as 4x^2 -41x +100 =0, factoring them gives us 4X^2 -16x -25x +100 =0. which can be solved as (4x-25)(x-4) , so x= 4 and 25/4.   so f^2 = 4 and 25/4   so f= +2 and minus 2 and +5/2 and minus 5/2   The two greatest values are +2 and +5/2. so their sum 2+5/2 =9/2 = 9/2
<result>B</result>
If 4f^4 − 41f^2 + 100 = 0, then what is the sum of the two greatest possible values of f ?