# What is the equation of the line normal to #f(x)=-4x^2 -5x +1 # at #x=-3#?

##### 1 Answer

Feb 20, 2016

#### Explanation:

Let

This is the gradient of the tangent

At

If the gradient of the normal is

To get the value of

The equation of the normal line is of the form:

So the equation is:

This is shown here:

graph{(-4x^2-5x+1-y)(-x/19-383/19-y)=0 [-80, 80, -40, 40]}