How do you convert 2=(3x+7y)^2-x2=(3x+7y)2x into polar form?

1 Answer
Dec 17, 2017

29r^2-20r^2cos(2theta)+21r^2sin(2theta)-rcos(theta)-2=029r220r2cos(2θ)+21r2sin(2θ)rcos(θ)2=0

Explanation:

2=(3x+7y)^2-x2=(3x+7y)2x

9x^2+42xy+49y^2-x=29x2+42xy+49y2x=2

After using x=rcos(theta)x=rcos(θ) and y=rsin(theta)y=rsin(θ) transormation,

9r^2(cos(theta))^2+42r^2*cos(theta)*sin(theta)+49r^2(sin(theta))^2-rcos(theta)=29r2(cos(θ))2+42r2cos(θ)sin(θ)+49r2(sin(θ))2rcos(θ)=2

9r^2*(1+cos(2theta))/2+21r^2*sin(2theta)+49r^2(1-cos(2theta))/2-rcos(theta)=29r21+cos(2θ)2+21r2sin(2θ)+49r21cos(2θ)2rcos(θ)=2

29r^2-20r^2cos(2theta)+21r^2sin(2theta)-rcos(theta)-2=029r220r2cos(2θ)+21r2sin(2θ)rcos(θ)2=0