1.

The sum to the n term of the series \[\cos e{{c}^{-1}}\sqrt{10}+\cos e{{c}^{-1}}\sqrt{50}+\cos e{{c}^{-1}}\sqrt{170}+...\]\[+\cos e{{c}^{-1}}\sqrt{({{n}^{2}}+1)({{n}^{2}}+2n+2)}\]

A. \[{{\tan }^{-1}}(n+1)-\pi /4\]
B. \[\pi /4\]
C. \[{{\tan }^{-1}}(n+1)\]
D. 1
Answer» B. \[\pi /4\]


Discussion

No Comment Found

Related MCQs