# What is the equation of the line normal to #f(x)=9x^2 - 28x - 34 # at #x=-1#?

##### 1 Answer

Dec 29, 2016

#### Explanation:

let

**1) find the gradient of the normal**

This is done in two parts

(i) find gradient of tangent

(ii) the normal is perpendicular to the tangent .

**2) find the eqn. of normal**

use

need to find