Question

Find the average rate of change of f(x) = -x² + 3x + 1 from x=2 to x = 5.

Simplify your answer as much as possible.

Answer 1

The average rate of change is: -4

Explanation:

So to solve this we just need to plug our numbers into the formula. We are using the formula f(b) - f(a)b - a where “a” and “b” are our numbers. So we are given the intervals x=2 and x=5. When we see that we can rewrite it as (2,0) and (5,0). This is because when it is telling us just “x” we know “y” (the second number in the parentheses) is 0. So just plugging in the numbers we get: (-(5)2+3(5)+1)-(-(2)2+3(2)+1)(5 - 2). Solving it we get -4.