# What is the equation of the normal line of #f(x)=2x^3-x^2-3x+9# at #x=-1#?

##### 1 Answer

Let's first find what point the tangent passes through, given

#### Explanation:

Therefore, the tangent passes through

Now that we know this, we must differentiate the function.

By the power rule:

The slope of the tangent is given by evaluating

The slope of the tangent is

This means the slope of the normal line is

Hopefully this helps!