How do you convert y= 3x^2 -2x+4xy^2 y=3x22x+4xy2 into a polar equation?

1 Answer
Jan 19, 2018

4r^2costhetasin^2theta+3rcos^2theta-(2costheta+sintheta)=04r2cosθsin2θ+3rcos2θ(2cosθ+sinθ)=0

Explanation:

The relation between polar coordiates (r,theta)(r,θ) and Cartesian corrdinates (x,y)(x,y) is given by x=rcosthetax=rcosθ and y=rsinthetay=rsinθ

Hence we can write y=3x^2-2x+4xy^2y=3x22x+4xy2 as

rsintheta=3r^2cos^2theta-2rcostheta+4r^3costhetasin^2thetarsinθ=3r2cos2θ2rcosθ+4r3cosθsin2θ

or 4r^2costhetasin^2theta+3rcos^2theta-(2costheta+sintheta)=04r2cosθsin2θ+3rcos2θ(2cosθ+sinθ)=0