How do you convert 2y= -x^2+3x 2y=x2+3x into a polar equation?

1 Answer

The polar equation is
color(blue)(r=(3*cos theta-2*sin theta)/cos^2 theta)r=3cosθ2sinθcos2θ

Explanation:

To convert 2y=-x^2+3x2y=x2+3x

Use x=r*cos thetax=rcosθ and y=r*sin thetay=rsinθ

Let's do it

2y=-x^2+3x2y=x2+3x

2(r*sin theta)=-(r*cos theta)^2+3(r*cos theta)2(rsinθ)=(rcosθ)2+3(rcosθ)

2*r*sin theta=-r^2*cos^2 theta+3*r*cos theta2rsinθ=r2cos2θ+3rcosθ

divide both sides of the equation by rr

(2*r*sin theta)/r=(-r^2*cos^2 theta)/r+(3*r*cos theta)/r2rsinθr=r2cos2θr+3rcosθr

(2*cancelr*sin theta)/cancelr=(-cancelr^2*cos^2 theta)/cancelr+(3*r*cos theta)/cancelr

2*sin theta=-r*cos^2 theta+3*cos theta

Transposition

r*cos^2 theta=3*cos theta-2*sin theta

divide both sides by cos^2 theta

(r*cos^2 theta)/cos^2 theta=(3*cos theta-2*sin theta)/cos^2 theta

(r*cancelcos^2 theta)/cancel(cos^2 theta)=(3*cos theta-2*sin theta)/cos^2 theta

color(red)(r=(3*cos theta-2*sin theta)/cos^2 theta)

God bless ....I hope the explanation is useful.