# What is the equation of the line normal to # f(x)=(x-1)(x+2) # at # x=0#?

##### 1 Answer

Jan 14, 2018

#### Explanation:

Firstly, just expand the brackets so:

Differentiate:

Find

So we now the gradient of the line is is

We need a point on the line and we know it should pass through the point:

So

Substitute into the equation of a line: