# How do you find the equation for the lines that are tangent and normal to the curve #y=1+cosx# at the point #(pi/2, 1)#?

##### 1 Answer

Sep 1, 2017

Start with the derivative

#### Explanation:

For

At

This is the slope of the tangent line.

Use the point-slope form of a line to find its equation.

In this case

Solve for y.

The normal is perpendicular to the tangent.

So, if

In this case, the normal slope is

Use the same point, and the point-slope form of a line, to obtain the equation of the normal line.