Question

When $\theta ={45}^{\circ },sin\theta +cos\theta =$ .

• A. $\frac{1}{\sqrt{2}}$
• B. $\sqrt{2}$
• C. $\frac{1}{\sqrt{3}}$
• D. $\sqrt{3}$

Answer 1

The correct option is B $\sqrt{2}$

When $\theta ={45}^{\circ }$, $sin\theta =\frac{1}{\sqrt{2}}$ and $cos\theta =\frac{1}{\sqrt{2}}$
$⟹sin\theta +cos\theta =\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{2}}=\frac{2}{\sqrt{2}}=\sqrt{2}$