I have the following integral as part of a calculation $$\int_{-A}^{A} \int_{-A}^{A} \frac{1}{(z^2 + d^2)^3} dz dx, $$ where $A$ is a constant. I am given the condition $d \gg z$ so I am wondering if it is permissible to expand the integrand using the binomial expansion to make the integration more tractable? Is it ok? Could someone explain this?
Thanks.