How do you write the equation using polar coordinates given x^2=4yx2=4y?

1 Answer
Oct 11, 2016

Substitute rcos(theta)rcos(θ) for x and rsin(theta)rsin(θ) for y.

Answer: r = 4sin(theta)/cos^2(theta)r=4sin(θ)cos2(θ)

Explanation:

Substitute rcos(theta)rcos(θ) for x and rsin(theta)rsin(θ) for y:

(rcos(theta))^2 = 4(rsin(theta))(rcos(θ))2=4(rsin(θ))

r^2cos^2(theta) = 4rsin(theta)r2cos2(θ)=4rsin(θ)

Divide both sides by rcos^2(theta)rcos2(θ):

r = 4sin(theta)/cos^2(theta)r=4sin(θ)cos2(θ)