What is sinα - sinβ?
\(\, 2\cos\frac{\alpha + \beta}{2} \, \sin\frac{\alpha - \beta}{2} \)
\(\, 2\sin\frac{\alpha + \beta}{2} \, \sin\frac{\alpha - \beta}{2} \)
\(\, 2\cos\frac{\alpha - \beta}{2} \, \sin\frac{\alpha + \beta}{2} \)
\(\, 2\cos\frac{\alpha + \beta}{2} \, \cos\frac{\alpha - \beta}{2} \)