# What is the equation of the normal line of #f(x)=-x^4+2x^3-12x^2-13x+3# at #x=-1#?

##### 1 Answer

Feb 8, 2016

#### Explanation:

Let

At

If the gradient of the normal line is

The value of

The equation of the normal is of the form:

So the equation of the normal is:

This is shown here:

graph{(y+x^4-2x^3+12x^2+13x-3)(y+x/10-62/21)=0 [-20, 20, -10, 10]}