Hello, animesh271094!
I found two ways . . . Neither is "easy".
Partial Fractions
We find that: .
We have: .
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
Substitution
Let
We have: .
. .
. .
Back-substitute: .
I tried to substitute as 't'. But that failed.
Then i divided all terms by , and that didnt give me any result too..
Finally, when i saw the answer at the back, i realized that i could write this as a sum of 2 terms..
But is there any easy method to do this? Without going through all this..?