Answer:
cos(x - 3 pi /2)= -7/25
Step-by-step explanation:
Lets remember the following relationship.
cos(a-b)=cos(a)*cos(b)+sin(a)*sin(b)
if we evaluate 'a'= x and b=3 pi /2 we have:
cos(x-3 pi /2)=cos(x)*cos(3 pi /2)+sin(x)*sin(3 pi /2)
Since cos(3 pi /2)=0, sin(3 pi /2)=-1
We have
cos(x - 3 pi /2) =-sin(x)
Since sin(x) = 7/25 as stated in the problem, we have the final result:
cos(x - 3 pi /2)= -7/25
