# A double integral need help

How to evaluate this integral? $$\large\int_0^\infty\int_{\sqrt{\gamma}}^\infty\text{e}^{\left(-\frac{t^2}{2}\right)}\text{d}t\cdot{\frac{N_0}{C}}\text{e}^{\left(-\frac{\gamma N_0}{C}\right)}\text{d}\gamma$$

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Once again, a question from you with absolutely no context or no thoughts of your own. Despite the fact that you've been asked numerous times to improve your questions. –  mrf Feb 25 '13 at 14:21

I think, if you change the order of the limits of integrals, everything will be OK. I mean $$k\int_{t=0}^\infty\exp(-t^2/2)\int_{\gamma=0}^{t^2}\exp(-k\gamma)d\gamma ~dt,~~~k=N_0/C$$
+1${}{}{}{}{}{}{}{}$ –  amWhy Feb 26 '13 at 0:52