Math Help - Double integration

1. Double integration

Need some help soving this double integral:

integral sign (0 to 1) integral sign (tan^-1(y) to pi/4) secx dxdy.

Help will be appreciated.

2. Re: Double integration

Hey mrmaaza123.

In this forum you should be able to evaluate the dx limits first then then the dy limits after.

Try doing that by integrating sec(x)dx with the appropriate limits and show us what you got.

3. Re: Double integration

Well i actually did get that far, and got
integral sign (0 to 1) ln(sqrt2 +1)+ln((sec(tan)^-1(y)) +y) dy
then i used the identity (tan(x))^2+1 = (sec(x))^2 to get ,

integral sign (0 to 1) ln(sqrt2+1) - ln(sqrt(y^2+1) +y) dy

this is where i got stuck. Do i proceed using by parts ?

4. Re: Double integration

I'd give parts a go and see what you get by setting dv = 1 and u = ln(sqrt(y^2 + 1) + y). You should get rid of the logarithm and the rest will be simpler.