Question

Find the value of $\cos 1^{\circ }\cos 2^{\circ }\cos 3^{\circ }.....\cos {180}^{\circ }$.

• A. $1$
• B. $-1$
• C. $0$
• D. None of these

Answer 1

Answer: (C)

$0$

We know that $\cos {180}^{\circ }=\cos 0˚=0$,

So given product,

$\cos 1˚\cos 2˚\cos 3˚\cdots \cos 180˚=0$