How do you convert a polar equation when its x squared+ y squared =10?

Answer 1

that is of course a circle of radius sqrt 10, so r = sqrt 10 is the equation bu we will struggle on anyway.

y = r sin T
x = r cos T

r^2 sin^2 T + r^2 cos^2 T = 10
r^2 (sin^2 T + cos^2 T ) = 10
but sin^2 + cos^2 = 1
so
r = sqrt 10