my teacher has given us this integration
I dont get how this equals
the domain of integration can change? can anyone explain this me?
Your equations seem to have a few errors. I think what you meant is this:
Is that right? You are changing the variable from x to u using:
From this you get:
When you do this you have to change the limits of integration to conform to this new variable. So where initially you had a lower limit of x = 0, you now have . Likewise, the upper end becomes . And the new integral is: