Dear Cecilia,

please clarify your question. What are the variables of integration of the double integral? What is the region of integration? Without a bit more detail, at least I do not understand the subject of your question. Are you familiar with differential forms?

Best regards

Herbert

the variables for integration is x and beta Mr.

i would to integrate the double integral by jacobian method but in journal that i've read, it's been explained that the transformation is y=x^beta but the transformation of beta=beta. beta=beta is called companion transformation. i do not understand the transformation beta=beta. do you know much about companion transformation? Please help me to solve this problem. thank you Mr