#### Amr Wael

##### Member level 4

I have been studying resolver of Motors lately , I understand the basics that there is a reference signal that is used to excite the resolver and then the resolver produces a sine and cosine signals whose amplitudes are proportional to the angle of the motor.

My question is why do we need both sine and cosine signals to compute the angle ? Isn't the Sine only enough for us to compute it as the cosine is always just a phase shift of the sine or is there another reason?

Thank you very much in advance

Amr