How do you convert x^2 + 5xy + y^2 = 7x2+5xy+y2=7 to polar form?
1 Answer
May 1, 2016
Explanation:
To convert from Cartesian to Polar coordinates use the following formulae which link them.
• x=rcostheta , y=rsintheta ∙x=rcosθ,y=rsinθ
rArr r^2cos^2theta+5r^2costhetasintheta+r^2sin^2theta=7⇒r2cos2θ+5r2cosθsinθ+r2sin2θ=7 remove the common factor of
r^2r2
rArrr^2(cos^2theta+5costhetasintheta+sin^2theta)=7⇒r2(cos2θ+5cosθsinθ+sin2θ)=7 Simplify using trig. identities
• sin^2theta+cos^2theta=1" and "∙sin2θ+cos2θ=1 and
• sin2theta=2sinthetacostheta∙sin2θ=2sinθcosθ
rArrr^2(1+5/2sin2theta)=7⇒r2(1+52sin2θ)=7
rArrr^2=7/(1+5/2sin2theta)⇒r2=71+52sin2θ