Question

How can we find the period of signal if it is equal to sum of two signals whose period is known?

Answer 1

If you are suppose to find period of sum of tow function such that, f(x)+g(x) given that period of f is a and period of g is b then period of total f(x)+g(x) will be LCM (a,b). But this technique has some constrain as it will not give correct answers in some cases. One of those case is, if you take f(x)=|sinx| and g(x)=|cosx|, then period of f(x)+g(x) should be pi as per the above rule but, period of f(x)+g(x) is not pi but (pi/2) So in general it is very difficult to identify correct answers for the questions regarding period. Most of the cases graph will help