The value of \( 2\sec^2(\tan^{-1}2)+3\,\mathrm{cosec}^2(\cot^{-1}3) \) is:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 40
The identities \( \sec^2\theta=1+\tan^2\theta \) and \( \mathrm{cosec}^2\theta=1+\cot^2\theta \) give both terms directly.
With \( \theta=\tan^{-1}2 \), \( \tan\theta=2 \):
\( \displaystyle \sec^2(\tan^{-1}2)=1+2^2=5 \)
With \( \theta=\cot^{-1}3 \), \( \cot\theta=3 \):
\( \displaystyle \mathrm{cosec}^2(\cot^{-1}3)=1+3^2=10 \)
So the value is
\( \displaystyle 2(5)+3(10)=10+30 \)
\( \displaystyle =40 \)