Question

$\tan^{2}\theta + \cot^{2}\theta$is

• A. $\geq 2$
• B. $\leq 2$
• C. $\geq - 2$
• D. None of these

Answer 1

Answer: (A)

$\geq 2$

Answer 2

We know that $\left( x - \frac{1}{x} \right)^{2} \geq 0 \Rightarrow x^{2} + \frac{1}{x^{2}} - 2 \geq 0$

Put $x = \tan\theta \Rightarrow \tan^{2}\theta + \cot^{2}\theta \geq 2$.