So base in your question where there is a function f(x)=2sin(x^2) on a interval the following are the answer to your question on A and B.
A. X=pi/2 is the value of X in the given interval.
B. the possible value of x is 1 2 and 3 which gives the value of 0.034, 0.14, 0.313
i hope i answered your question