1. Feb 27, 2016

### henil

i want to add two frequencies having same phase but different amplitudes, in what manner i can proceed ?

2. Feb 27, 2016

### Staff: Mentor

If you have two amplitudes $a_1, a_2$ and the same phase $φ$ then your waves are $a_ 1 \sin{φ}$ and $a_ 2 \sin{φ}$ so the resulting wave is $(a_1 + a_2) \sin φ$.

3. Feb 28, 2016

### sophiecentaur

The phases of any two signals with different frequencies will coincide momentarily at a rate equal to the difference in the frequencies
but they cannot 'have the same phase'. You can, of course, choose your time origin to be when the phases of both signals are both zero. This would make the starting equation simpler.
Could it be that you are adding two signals with the same frequency.