double integrals

• How to Change Variables and Bounds in a Double Integral
  Learn how to transform a double integral correctly: map the region, derive new bounds, include the absolute Jacobian, and check the result.
• How to Change Variables in a Double Integral
  To change variables in a double integral, transform the region and integrand, then multiply by the absolute Jacobian determinant.
• How to Set Up a Double Integral Over an Inequality-Defined Region
  To integrate over a region given by inequalities, sketch its boundary, find projection limits, and write the bounds in an order that covers it once.