Question

What is the value of $\cos 1^o\cos 2^o\cos 3^o.......\cos {90}^o$?

Answer 1

$\cos 1^o\cos 2^o\cos 3^o...\dots \cos {90}^o$

As $\cos {90}^o=0$

$\cos 1^o\cos 2^o\cos 3^o.....0$

$=0$.