I have the following expression:

NIntegrate[

Exp[-((2 t^2 u^2)/i^4)] t^2 BesselI[0, t/

i^4] (BesselI[-1, t/i^4] + BesselI[1, t/i^4]), {t, 0,

1}]/(2 NIntegrate[

Exp[-((2 t^2 u^2)/i^4)] + BesselI[0, t/i^4]^2, {t, 0, 1}])

For (u,i)=(0,4) it gives 0.000244141. What I wont is to find the pairs (u,i) which also give this value.

Because of the Besselfunktions it must be done numerically.

I have written the following program in mathematica:

Catch[Do[If[

NIntegrate[

Exp[-((2 t^2 u^2)/i^4)] t^2 BesselI[0, t/

i^4] (BesselI[-1, t/i^4] + BesselI[1, t/i^4]), {t, 0, 1}]/(

2 NIntegrate[

Exp[-((2 t^2 u^2)/i^4)] + BesselI[0, t/i^4]^2, {t, 0, 1}]) <

0.000244141, Throw[{u, i}]], {u, 0, 4}, {i, 3, 4, 0.001}]]

But it stops as soon as it finds values for (u,i) which fullfills the inequality. How do I make the program go on for u=2,3, 4...?

I think that maybe I can use Table to make this work, but I don´t know how to do it.

Please help me

Juliane