Wednesday

November 25, 2015
Posted by **Laila ** on Wednesday, July 30, 2014 at 11:05am.

What is the polar equation that is equivalent to the rectangular equation?

- PreCalculus -
**Laila**, Wednesday, July 30, 2014 at 11:06amSorry it's actually equal to 1 not 0

- PreCalculus -
**Steve**, Wednesday, July 30, 2014 at 3:25pmjust make the usual substitution.

y = rsinθ

x = rcosθ

so, that means

r^2sin^2θ/25 - r^2cos^2θ/9 = 1

r^2(9sin^2θ-25cos^2θ) = 225

r^2 = 225/(9sin^2θ-25cos^2θ)

see the expected vertical hyperbola at

http://www.wolframalpha.com/input/?i=plot+r^2+%3D+225%2F%289sin^2%CE%B8-25cos^2%CE%B8%29