Question

How to transform rectangular points to polar? E. g., A(-3, -3)?
And how to do it from polar to rectangular? E. g., B(2, 3/2pi)?

Answer 1

to change rectangular to polar in A(-3, -3), use the fact that :
\[\large r=\sqrt{x^2+y^2} \]
\[\large \theta=arctan(\frac{y}{x}) \]

to change from polar to rectangular in \(\large (2,\frac{3\pi}{2}) \), use:
\[\large x=rcos\theta \]
\[\large y=rsin\theta \]

Answer 2

in A(-3, -3):
r = sqrt(18) = 3sqrt2
theta = arctan(-3/-3) = 5pi/4
so in polar form it's (3sqrt2, 5pi/4)

Answer 3

Thank you. I get it now.