Consider the function f(x)=3x.
a. Determine an expression, in terms of a and h, for the average rate of change between the points (a,f(a)) and ( a + h, f(a+h) ) for the function . Show all steps needed to find a simplified algebraic expression.
b. Using your expression from (a), determine the average rate of change from x = -1 to x = 2. Express your answer as an exact value - no decimals!
the average rate of change is just the slope of the secant. That is,
(f(a+h) - f(a))/((a+h)-a)