### Home > CALC > Chapter 4 > Lesson 4.2.1 > Problem 4-47

4-47.

Use the Power Rule to find *f *′(*x*) for *f*(*x*) = (*x*^{2} + l )(*x* − 4) by first expanding *f*(*x*)*. *Then, find the equation of the line tangent to *f*(*x*) at *x* = −3. Homework Help ✎

Write the tangent line in point-slope form.

Which function, *f*(*x*) or *f* '(*x*), can be used to find the slope? Which can be used to find the point?