Question

${\int }_{\frac{\pi }{6}}^{\frac{\pi }{4}}cosec2xdx=$

• A. log 3
• B. log $\sqrt{3}$
• C. log 9
• D. None of these

Answer 1

The correct option is D None of these

${\int }_{\frac{\pi }{6}}^{\frac{\pi }{4}}cosec2xdx=\frac{1}{2}[logtanx{]}_{\frac{\pi }{6}}^{\frac{\pi }{4}}$
$=\frac{1}{2}[logtan\frac{\pi }{4}-logtan\frac{\pi }{6}]=\frac{1}{2}log\sqrt{3}$