1.

The value of the integral ` int _(0)^(pi//2) log | tan x| dx `isA. ` pi log 2`B. 0C. `-pi log 2`D. None of these

Answer» Correct Answer - B
Let `l=int_(0)^(pi//2)log|tanx|dx" …(i)"`
`rArr" "l=int_(0)^(pi//2)log|tan((pi)/(2)-x)|" …(ii)"`
On adding Eqs. (i) and (ii), we get
`2l=int_(0)^(pi//2)log|tanxcotx|dx`
`=int_(0)^(pi//2)log1dx=0`
`rArr" "l=0`


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