Question

${\tan }^2\theta ={\sin }^2\theta +{\cos }^2\theta$, then $\theta =$.............

• A. $30$
• B. $45$
• C. $60$
• D. $90$

Answer 1

The correct option is B $45$

We know that, ${\sin }^2\theta +{\cos }^2\theta =1$

$⟹{\tan }^2\theta ={\sin }^2\theta +{\cos }^2\theta =1$
$⟹\tan \theta =1⟹\theta ={\tan }^{-1}\left(1\right)⟹\theta ={45}^o$

Hence, the answer is ${45}^o$.