integration 1992

Q) \int ( \frac{1}{\sqrt[3]{x} + \sqrt[4]{x}} + \frac{ln( 1 + \sqrt[6]{x}}{\sqrt[3]{x} + \sqrt[]{x}} ) dx

3 Answers

23
qwerty ·

put x = t12

dx = 12t11dt

I=12\int [{}\frac{1}{t^{4}+t^{3}}+\frac{log(1+t^{2})}{t^{4}+t^{6}}]t^{11}dt

I=12\int [{}\frac{t^{8}}{t+1}+\frac{t^{7}log(1+t^{2})}{1+t^{2}}]dt

I_{1}=12\int {}\frac{t^{8}dt}{t+1}

I_{2}=12\int \frac{t^{7}log(1+t^{2})}{1+t^{2}}dt

log(1+t^{2})={m}, dm = \frac{2tdt}{1+t^{2}}

so,I_{2}=6\int \frac{t^{6}log(1+t^{2})2tdt}{1+t^{2}}=6\int (e^{m}-1)^{3}mdm
wich u can do further easily ,

BTW nishant sir , LAtex isnt working ....

1
Euclid ·

thanx qwerty...i started up similarly bt was messed up... isnt it a bit lenghthy!!!!

no other shorter tracks???

23
qwerty ·

donno there may be , but by looking at the problem u must instantly try to remove root signs , bcz then in the next steps u will get some idea of how to solve further
i think jee during those days was full of such lengthy sums

Your Answer

Close [X]