CPM Homework Help : CALC Problem 4-47

Use the Power Rule to find $f^\prime(x)$ for $f(x) = (x^2 + 1 )(x-4)$ by first expanding $f(x)$ . Then, find the equation of the line tangent to $f(x)$ at $x =-3$ .

Hint 1:

Write the tangent line in point-slope form.

Hint 2:

Which function, $f(x)$ or $f^\prime(x)$ , can be used to find the slope? Which can be used to find the point?