The value of cos 9(^\circ) - sin 9(^\circ) is | Mathematics | SolveeIt | Solveeit

Today, August 18

Question

The value of cos 9 $^\circ$ - sin 9 $^\circ$ is

A

$-\frac{\sqrt{5-\sqrt{5}}}{2}$

B

$\frac{5+\sqrt{5}}{4}$

C

$\frac{1}{2}\sqrt{5-\sqrt{5}}$

D

none of these.

Answer

$\frac{1}{2}\sqrt{5-\sqrt{5}}$

Explanation

Solution

Answer (c) $\frac{1}{2}\sqrt{5-\sqrt{5}}$