# Thread: cartesian to polar integrals

1. ## cartesian to polar integrals

can someone help me with this? i don't really understand it. the cartesian double integral is:

(x^2+y^2)dydx

and the limits of integration for dy are -sqrt(1-y^2) and sqrt(1-y^2)
the limits of integration for dx are -1 and 1

so i know this graph is an ellipse.. but i don't know how to graph it, seeing that it's not an equation (like x^2+y^2=1). so i can't visualize exactly what it is, so i don't know how to visualize the polar graph. agh i'm completely confused. any hints at how to attack this beast?

2. Originally Posted by isuckatcalc
can someone help me with this? i don't really understand it. the cartesian double integral is:

(x^2+y^2)dydx

and the limits of integration for dy are -sqrt(1-y^2) and sqrt(1-y^2)
the limits of integration for dx are -1 and 1

so i know this graph is an ellipse.. but i don't know how to graph it, seeing that it's not an equation (like x^2+y^2=1). so i can't visualize exactly what it is, so i don't know how to visualize the polar graph. agh i'm completely confused. any hints at how to attack this beast?
The region of integration is a circle with centre at the origin and radius 1. You ought to be able to express this rgion using polar coordinates.

And you should know what x^2 + y^2 = in polar coordinates. As well, you should know what dx dy becomes in polar coordinates.

If you need more help please show yiour work and say where you're still stuck.