Saved Bookmarks
| 1. |
Find the fundamental period of `f(x)=cosxcos2xcos3xdot` |
|
Answer» Correct Answer - `pi` `f(x)=cosx cos2x cos 3x` `cosx,cos2x,` and `cos 3x` are periodic with period `2pi,pi,` and `(2pi)/(3)` L.C.M. of `(pi,2pi, (2pi)/(3))=2pi` But `f(x+pi)=cos(x+pi) cos(2x+2pi)cos(3x+3pi)` `=(-cosx)(cos 2x)(-cos 3x)` `=cosx cos 2x cos 3x` `=f(x)` Hence, period is `pi`. |
|