# Converting Rectangular to Polar

• Dec 8th 2009, 09:55 AM
megabust
Converting Rectangular to Polar
I am having a brain fade today, and just really need to make sure I am doing this correctly.

i am given ... Convert the rectangular equation x^2 + y^2 - 2y = 0

I think the answer is -2sin(theta) however I am missing a step to proove it.

and one other one on the reverse side... convert polar to rectangular

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

I am lost on that one.
any help is greatly appreciate
• Dec 8th 2009, 11:51 AM
mr fantastic
Quote:

Originally Posted by megabust
I am having a brain fade today, and just really need to make sure I am doing this correctly.

i am given ... Convert the rectangular equation x^2 + y^2 - 2y = 0

I think the answer is -2sin(theta) however I am missing a step to proove it.

and one other one on the reverse side... convert polar to rectangular

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

I am lost on that one.
any help is greatly appreciate

Straight forward substitution: $\displaystyle r^2 - 2r \sin \theta = 0$. Therefore ....
• Dec 8th 2009, 02:16 PM
megabust
I guess I assumed since it was easy that I was missing something.

And on the second one I figured out that I just multiply by the denom to get the form I need ... thanks for your help.