- #1
8614smith
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Homework Statement
Sketch the regions of integration, and evaluate the integral by choosing the best order of integration.
[tex]\int^{2\sqrt{ln2}}_{0}\int^{\sqrt{ln2}}_{y/2}exp(x^2)dxdy[/tex]
Homework Equations
integration by parts
The Attempt at a Solution
ive changed the order of integration and done the inner integral with respect to y to get this far..
[tex]\int^{\sqrt{ln2}}_{y/2}\int^{2\sqrt{ln2}}_{0}exp(x^2)dydx=\sqrt{ln2}\int^{2\sqrt{ln2}}_{y/2}exp(x^2)dx[/tex]
and now when i do a u substitution
[tex]u=x^2[/tex]
[tex]du=2xdx[/tex]
and that is how far i can get as i can't put the 'du' into the equation as it has a '2x' in it and i will be integrating with respect to 'u'. Integrating it the original way round just gets me to this problem straight away.
I just can't see any way of getting rid of the 2x?!