Cartesian equation for a polar curve?

Hi,

How do you find the Cartesian equation for r=2sinθ (0<=θ<π)?

Many, many thanks,

Froskoy.

phasor2010-01-24T13:35:00Z

Favorite Answer

r=√(x²+y²)
Θ=tan(-1)y/x

r=2sinθ
√(x²+y²=2sin(tan(-1)(y/x))
√(x²+y²=2y/√(x²+y²)
x²+y²=2y
(y-1)²+x²=1

the restriction (0<=θ<π) means only once around the circle so the equation is correct as is.