Question

Convert the polar equation r = 2 costheta in Cartesian equation form.

Answer 1

x² + y² - 2x = 0

Explanation:

r = sqrt(x² + y²)

x = r cos(theta)

r = 2 cos(theta)

Multiply both sides by r

r² = 2r cos(theta)

x² + y² = 2x

Answer 2

To transform from polar coordinates into Cartesian coordinates we have:

x = r x cos(theta)

y = r x sin(theta)

r^2 = x^2 + y^2

=> r = 2*cos(theta)

<=> r = 2*(x/r)

<=> 2x = r^2

<=> 2x = x^2 + y^2

Hope this helps!

:)