CPM Homework Help : APCALC Problem 4-10

Use the Power Rule to write an equation for $f^\prime$ if $f\left(x\right) = \left(x + 4\right)\left(x – 3\right)$ by first expanding $f$ . Then, write the equation of the line tangent to $f$ at $x = 3$ .

Hint:

In order to find the equation of the tangent line at $x = 3$ , you will need to find a point on the line and the slope at $x =3$ .

Step 1:

To find a point, evaluate $f\left(3\right)= \text{ _________}$

Step 2:

To find the slope, evaluate $f^\prime \left(3\right)= \text{________}$

Step 3:

Put it all together in point-slope form: $y −y_{1} = m\left(x −x_{1}\right)$