How do you convert r = -sin3θ into rectangular form?

1 Answer
Sep 25, 2016

We know the relations

x=rcostheta and y =rsintheta

where r and theta are the polar coordinate of a point having rectangular coordinate (x,y)
So r^2=x^2+y^2

Now the given relation is

r=-sin3theta=4sin^3theta-3sintheta

=>r^4=4r^3sintheta-3r^3sintheta

=>r^4=4(rsintheta)^3-3r^2*rsintheta

=>(x^2+y^2)^2=4y^3-3(x^2+y^2)y

This is the rectangular form of the given polar equation.