Find the value of the following.

​$$\frac{\cos 15^\circ - \sin 75^\circ}{\cos 15^\circ + \sin 75^\circ}$$​​

Correct option is B

Solution:

sin(75°) =  cos(15°):

sin(90° - θ) = cos(θ), we know that: sin(75°) = cos(15°)

Substitute sin(75°) with cos(15°):

​$$\frac{\cos 15^\circ - \cos 15^\circ}{\cos 15^\circ + \cos 15^\circ}$$​​

​$$\frac{0}{2 \cos 15^\circ} = 0$$​​