Q. The value of the expression $\cos 1{^\circ}.\cos{2{^\circ}}\ldots..\cos{179{^\circ}}$ equals
A) 0
B) 1
C) $1/\sqrt{2}$
D) $- 1$
Explanation
(a)
$\cos 1{^\circ}.\cos{2{^\circ}}\ldots..\cos{179{^\circ}}$
$= \cos 1{^\circ}.\cos{2{^\circ}}\ldots.\cos{90{^\circ}}.\cos{179{^\circ}}$
$= 0$ $\lbrack\because\cos{90{^\circ} = 0}\rbrack$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.