Question

cos$1^{\circ }$ $\times$ cos$2^{\circ }$ $\times$ cos$3^{\circ }$ $\times$……..$\times$ cos ${180}^{\circ }$ is equal to ____.

• A. 1
• B. 0
• C. $\frac{1}{2}$
• D. -1

Answer 1

Answer: (B)

0

We know that, $cos{90}^{\circ }=0$
The given expression
$cos{1}^{\circ }$ $\times$ $cos{2}^{\circ }$ $\times$ $cos{3}^{\circ }$ $\times$....$\times$ $cos{90}^{\circ }$ $\times$……..$\times$ $cos{180}^{\circ }$ reduces to zero as it contains $cos{90}^{\circ }$ which is equal to 0.