f an object moves along the​ y-axis (marked in​ feet) so that its position at time x​ (in seconds) is given by f (x )equals 117 x minus 13 x squared​, find the following.

​(A) The instantaneous velocity function v equals f prime (x )
​(B) The velocity when xequals0 and xequals3 sec
​(C) The​ time(s) when vequals0