Question

Find a polar equation that has the same graph as the equation in x and y.
x^2 + y^2 = 5

Answer 1

x^2 + y^2 can be replaced by r^2 to obtain the polar equation equivalent to x^2 + y^2 = 5.  Thus, r^2 = 5, and r = sqrt(5).  That's all that's necessary.  No matter what the angle is, r will always be sqrt(5).