# How do you graph #r = 12cos(theta)#?

##### 1 Answer

Set your compass to a radius of 6, put the center point at

#### Explanation:

Multiply both sides of the equation by r:

Substitute

The standard form of this type of equation (a circle) is:

To put the equation in this form, we need to complete the square for both the x and y terms. The y term is easy, we merely subtract

To complete the square for the x terms, we add

We can use the pattern,

Substitute 6 for h into the equation of the circle:

We know that the first three terms are a perfect square with h = 6:

This is a circle with a radius of 6 and a center point