A) \[\frac{\pi }{4}\]
B) \[\frac{3\pi }{4}\]
C) \[\frac{-\pi }{4}\]
D) \[\frac{5\pi }{4}\]
Correct Answer: B
Solution :
[b] Principal value of \[co{{t}^{-1}}(-1)\] \[=co{{t}^{-1}}\left( -\cot \frac{\pi }{2} \right)={{\cot }^{-1}}\cot \left( \pi -\frac{\pi 4}{{}} \right)\] \[=co{{t}^{-1}}\left( -\cot \frac{\pi }{2} \right)={{\cot }^{-1}}\cot \left( \frac{3\pi }{4} \right)=\frac{3\pi }{4}.\]
You need to login to perform this action.
You will be redirected in
3 sec
