How do you convert #x^2 + y^2 = 4x + 4y# to polar form? Trigonometry The Polar System Converting Between Systems 1 Answer Narad T. Oct 15, 2016 #r=4costheta+4sintheta# Explanation: #x=rcostheta# #y=rsintheta# #LHS=x^2+y^2=r^2cos^2theta+r^2sin^2theta=r^2(cos^2theta+sin^2theta)=r^2# As #cos^2theta+sin^2theta=1# #RHS=4rcostheta+4rsintheta=4r(cos theta+sintheta)# LHS=RHS #r^2=4r(costheta+sintheta)# Finally #r=4(costheta+sintheta)# Answer link Related questions How do you convert rectangular coordinates to polar coordinates? When is it easier to use the polar form of an equation or a rectangular form of an equation? How do you write #r = 4 \cos \theta # into rectangular form? What is the rectangular form of #r = 3 \csc \theta #? What is the polar form of # x^2 + y^2 = 2x#? How do you convert #r \sin^2 \theta =3 \cos \theta# into rectangular form? How do you convert from 300 degrees to radians? How do you convert the polar equation #10 sin(θ)# to the rectangular form? How do you convert the rectangular equation to polar form x=4? How do you find the cartesian graph of #r cos(θ) = 9#? See all questions in Converting Between Systems Impact of this question 3822 views around the world You can reuse this answer Creative Commons License