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

##### 1 Answer

Dec 18, 2015

#### Explanation:

Given:

So the point of intersection is going to be at

Expanding the given equation we get

So

And at

Therefore the slope of the normal will be

Using the slope-point form for the normal we have

which can be simplified as

(Sorry about the image quality. I've been having trouble with the graph method and this is an attempt to overlay 2 separate graphs snipped from the screen).