Suppose that an object moves along the y-axis so that its location is y=x2+3x at time x. (here y is in meters and x is in seconds.)
(a) find the average velocity (the average rate of change of y with respect to x) for x changing from 1 to 7 seconds.
(b) find the average velocity for x changing from 4 to 4+h seconds.
(c) find the instantaneous velocity at x=4 seconds.

Consider the function f left parenthesis x right parenthesis equals 4 x squared minus 3 x minus 1f(x)=4x2−3x−1 and complete parts (a) through (c). (a) find f left parenthesis a plus h right parenthesis f(a+h); (b) find startfraction f left parenthesis a plus h right parenthesis minus f left parenthesis a right parenthesis over h endfraction f(a+h)−f(a) h; (c) find the instantaneous rate of change of f when aequals=77.