Question

Find the derivative of f(x) = -2x2 + 11x at x = 9.

Answer 1

The value of the derivative at x = 9 is -25

Explanation:

Here in this question, we are told to find the derivative of the given equation at the point where x = 9

What we need to do here is simply, differentiate f(x), then substitute that value x = 9 into the differentiated equation

In notation form, what we are to find is f’(9)

So;

f(x) = -2x^2 + 11x

f’(x) = -4x + 11

So therefore;

f’(9) = -4(9) + 11

f’(9) = -36 + 11

f’(9) = 11-36

f’(9) = -25