Pre Calculus
posted by Jack .
As x increases from p/4 to 3p/2, the value of sin(x) :
A.increases throughout the interval
B.decreases at first, then increases
C.increases at first, then decreases
D.decreases throughout the interval
E.none of the above
please explain why the answer is as it is, I don't understand this at all, please help :)

This only makes sense if your "p" is pi, and x is an angle expressed in radians.
The sin of pi/4 is 0.7071
Then sin x rises to +1 at x = pi/2, and falls to 1 at x = 3 pi/2
The correct answer is therefore C