Plzz tell 30(2). 30. Prove that :
(ii) tan 560 = cos110+sin110
cos 110 — sin 110
(i) sin (x + y) sin (x — y) + sin (y + z) sin (y — z) + sin (z + x) sin (z —x) = 0
(ii) 1 + tan x tan x —
x
— — sec x = tan x cot — — I
2
31. Prove that : tan 13x = tan 4x + tan 9x + tan 4x tan 9x tan 13x.
32. Prove that : cos 2x cos 2 y + sin2 (x — y) — sin2 (x + y) = cos (21 + 2y).
cos(x + y)
1
(i) If cot x cot y = 2, show that
33.
cos(x—y) ¯ 3
sin (A — B) m — 1
= m tan B, prove that
sin(A + B) ¯ m +1
(ii)lfta A
(iii) If a +
tan a
= Y and
tan
x
— then rove that sin (a —
sin y.
