What the is the polar form of y = y/x+x^2(2-y)^2 y=yx+x2(2y)2?

1 Answer
Apr 24, 2017

Use the conversion:
x=r cos(theta)x=rcos(θ)
y=r sin(theta)y=rsin(θ)

Now substitute:
r sin(theta)=(rsin(theta))/(rcos(theta))+(rcos(theta))^2(2-rsin(theta))^2rsin(θ)=rsin(θ)rcos(θ)+(rcos(θ))2(2rsin(θ))2

Expand the final term:
r sin(theta)=(sin(theta))/(cos(theta))+r^2cos^2(theta)(4-2rsin(theta)+r^2sin^2(theta))rsin(θ)=sin(θ)cos(θ)+r2cos2(θ)(42rsin(θ)+r2sin2(θ))

Multiply by cos(theta)cos(θ):
r sin(theta)cos(theta)=sin(theta)+r^2cos^3(theta)(4-2rsin(theta)+r^2sin^2(theta))rsin(θ)cos(θ)=sin(θ)+r2cos3(θ)(42rsin(θ)+r2sin2(θ))

At this point it is not looking like the solution can be represented 'nicely'. You could try converting everything into sinsin