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

##### 1 Answer

Jan 11, 2016

#### Explanation:

Differentiate the function to find its gradient.

Use the point

The gradient of the normal is the negative reciprocal of the gradient of the tangent at a point.

So the gradient of the normal at

To find the coordinates of the point the normal passes through, substitute

So coordinates are

Equation of a line is: