To convert a polar coordinate (r,theta)(r,θ) in Cartesian form we use relation r=sqrt(x^2+y^2)r=√x2+y2, rcostheta=xrcosθ=x, rsintheta=yrsinθ=y and theta=tan^(-1)(y/x)θ=tan−1(yx). Using these relations
r^2−4r=sintheta−5costhetar2−4r=sinθ−5cosθ cann be written as
r^3-4r^2=rsintheta−5rcosthetar3−4r2=rsinθ−5rcosθ or
(x^2+y^2)^(3/2)-4(x^2+y^2)=y-5x(x2+y2)32−4(x2+y2)=y−5x or