# Parametric curve

1. Oct 25, 2009

### Somefantastik

1. The problem statement, all variables and given/known data
Find parameterizations for the circle of radius 3 about the point (3,4)

2. Relevant equations

3. The attempt at a solution

The circle of radius 3 about the origin looks like cos2t + sin2t = 3

But I can't figure out how to parameterize it around (3,4), any advice?

2. Oct 25, 2009

### Office_Shredder

Staff Emeritus
If you have a circle around the origin, and you want to move it so that it's a circle around the point (3,4) what vector do you have to add to your circle? Think about it in terms of transformations on the plane. Hint: You want the center of the circle around the origin to move to the center of the circle around (3,4)

3. Oct 25, 2009

### Somefantastik

the circle will be (x-3)2+(y-4)2 = 9, but how do I parameterize that?

4. Oct 26, 2009

### HallsofIvy

Use the fact that $sin^2 t+ cos^2 t= 1$ for all t.