Question

The value of $\cos 1\cos 2\cos 3.....\cos 179$ is

• A. $\frac{1}{\sqrt{2}}$
• B. $0$
• C. $1$
• D. None of these.

Answer 1

The correct option is B $0$

$\cos 1\cos 2\cos 3...........\cos 179$

$=\cos 1\cos 2\cos 3..........\cos \mathrm{90........}\cos 179$

$=\cos 1\cos 2\cos \mathrm{3.............}\left(0\right).........\cos 179$ since $\cos {90}^{\circ }=0$

$=0$

Ans. option B