Question

If ${\tan }^{2}x=1$ , then $x$ is equal to

• A. $2n\pi +(-1{)}^n\frac{\pi }{4},n\in Z$
• B. $n\pi \pm \frac{\pi }{4},n\in Z$
• C. $2n\pi +\frac{\pi }{4},n\in Z$
• D. $n\pi +\frac{\pi }{4},n\in Z$

Answer 1

The correct option is B $n\pi \pm \frac{\pi }{4},n\in Z$

${\tan }^{2}x=1\Rightarrow {\tan }^{2}x={\tan }^2\frac{\pi }{4}\Rightarrow x=n\pi \pm \frac{\pi }{4},n\in Z$