SEAMO 2027 - Paper E - SET 02 - Self-study Question 12

Evaluate $$\frac{\cos^4 15^\circ+\sin^4 15^\circ+2\sin^2 15^\circ\cos^2 15^\circ}{\cos^6 15^\circ+\sin^6 15^\circ+3\sin^2 15^\circ\cos^2 15^\circ}.$$