Question

The value of $\cos {10}^{\circ }-\sin {10}^{\circ }$

• A. Positive
• B. Negative
• C. $0$
• D. $1$

Answer 1

Answer: (A)

Positive

Let, $y=\cos {10}^{\circ }-\sin {10}^{\circ }$

$\because$ for any value of $0\le \theta <\frac{\pi }{4}$
$\cos \theta >\sin \theta$

therefore, $\cos {10}^{\circ }>\sin {10}^{\circ }$

$\Rightarrow y$ is positive.