Home › UP Board Class 10 › Mathematics › Choose the correct value of $\dfrac{1+\tan^2 A}{…
Choose the correct value of $\dfrac{1+\tan^2 A}{1+\cot^2 A}$.
A$\sec^2 A$
B$-1$
C$\cot^2 A$
D$\tan^2 A$
Answer & Solution
Correct answer: D. $\tan^2 A$
Using identities, $1+\tan^2 A=\sec^2 A$ and $1+\cot^2 A=\cosec^2 A$. So
$$\frac{1+\tan^2 A}{1+\cot^2 A}=\frac{\sec^2 A}{\cosec^2 A}=\frac{1/\cos^2 A}{1/\sin^2 A}=\frac{\sin^2 A}{\cos^2 A}=\tan^2 A.$$
Thus option D is correct.
Related questions
What is the derivative of $x^x$ for $x>0$?If $y=x^{\tan^{-1}x}$, then $\dfrac{dy}{dx}$ equalsThe derivative of $ in^{-1}x$ isThe derivative of $\cos^{-1}x$ isWhat is $\dfrac{d}{dx}(\tan^{-1}x)$?If $y=\dfrac{1}{x^n}$, then $\dfrac{dy}{dx}$ isWhich identity is correct?For the expression $ qrt{1-x^2}$, a useful trigonometric substitution is