Without using trigonometric tables, evaluate: (i)cos 48∘−sin 42∘ (ii)cosec 31∘−sec 59∘ (iii)cot 34∘−tan 56∘ (iv)cos2 13∘−sin2 77∘ [4 MARKS]

Without using trigonometric tables, evaluate: (i)cos 48∘−sin 42�

1.	Without using trigonometric tables, evaluate: (i)cos 48∘−sin 42∘ (ii)cosec 31∘−sec 59∘ (iii)cot 34∘−tan 56∘ (iv)cos2 13∘−sin2 77∘ [4 MARKS]
Answer» Without using trigonometric tables, evaluate: $(i) c o s 48^{\circ} - s i n 42^{\circ}$ $(i i) c o s e c 31^{\circ} - s e c 59^{\circ}$ $(i i i) c o t 34^{\circ} - t a n 56^{\circ}$ $(i v) c o s^{2} 13^{\circ} - s i n^{2} 77^{\circ}$ [4 MARKS]