Answer the following without using a calculator

MATHEMATICS · Multi-part · A Level · Mathematics · Trigonometry · Trigonometry

Problem

Answer the following without using a calculator. Give all results in simplest surd form. (i) Find the exact value of

\sin 75^{\circ}

. (ii) Find the exact value of

\cos 15^{\circ}

. (iii) Hence evaluate

\sin 75^{\circ}+\cos 15^{\circ}