# Dx dy where R is the unit circle.

1. Aug 4, 2009

### squenshl

Given the double integral $$\int\int_R$$ $$\sqrt{}x^2+y^2$$ dx dy where R is the unit circle.
We are only given the equation for the unit circle but don't we need more equations so I can change the equations to a single variable and then find the Jacobian so how do I find the Jacobian.
How do I find a point interior to R at which the Jacobian vanishes.

2. Aug 4, 2009