# Thread: From polar form to rectangular form..help!

1. ## From polar form to rectangular form..help!

Here is the problem...

Write the polar equation r = cos [theta] + sin [theta] in rectangular form.

2. Originally Posted by skippydurge
Here is the problem...

Write the polar equation r = cos [theta] + sin [theta] in rectangular form.

the parameters in polar coordinates are r and theta
the parameters in rectangular coordinates are x and y
these are related be
x= r cos(theta)
y = r sin(theta)
x^2 + y^2 =r^2
your equation :r = cos [theta] + sin [theta]
multiply whole equation by r
r^2 = rcos [theta] + rsin [theta]
x^2 + y^2 = x +y

3. Thank you very much!