Question
∫∞0 log(1+x2)1+x2dx=
Answer: Option B
:
B
LetI=∫∞0log(1+x2)1+x2dx
Putx=tanθ⇒dx=sec2θdθ,
∴I=∫n20log(secθ)2dθ=2∫n20logsecθdθ
=−2∫n20logcosθdθ =−2.π2log12=−πlog12=πlog2
Was this answer helpful ?
:
B
LetI=∫∞0log(1+x2)1+x2dx
Putx=tanθ⇒dx=sec2θdθ,
∴I=∫n20log(secθ)2dθ=2∫n20logsecθdθ
=−2∫n20logcosθdθ =−2.π2log12=−πlog12=πlog2
Was this answer helpful ?
Submit Solution