How do you convert y=x^2y=x2 into a polar equation?

1 Answer
Jan 20, 2016

r = tanthetasectheta r=tanθsecθ

Explanation:

using the links between Cartesian and Polar coordinates.

• x = rcostheta x=rcosθ

• y = r sintheta y=rsinθ

We can now write the above equation as :

r sintheta = ( r costheta )^2 = r^2 cos^2theta rsinθ=(rcosθ)2=r2cos2θ

(dividing both sides by r )

( rsintheta)/r = (r^2cos^2theta)/r rsinθr=r2cos2θr

sintheta = rcos^2theta sinθ=rcos2θ

rArr r = sintheta/costheta xx 1/costheta = tantheta sectheta r=sinθcosθ×1cosθ=tanθsecθ