integration over a circle VS rectangle

I have entered a function (fun), converted it to the polar domain (polarfun)

q0 is the function integration over a circle with radius 400um centered in the origin

q3 is the function integration over a square with dimensions 800*800 um*um

q3 is expected to be greater than q0 as the square has a greater area. However, the results are as shown!

what could be the mistake in my code?

Answer 1

[Bjorn Gustavsson]

Dont forget the basics:

dxdy = rdrdtheta

HTH