Two waves are represented by the equations \(y_1 = a\sin(\omega t+kx+0.57)~\text{m}\) and
\(y_2 = a\cos(\omega t+kx)~\text{m},\) where \(x\) is in meters and \(t\) in seconds. The phase difference between them is:
1. \(1.25\) rad
2. \(1.57\) rad
3. \(0.57\) rad
4. \(1.0\) rad