.Q-19 Prove that : 3 cos 68º.cosec22°43º. tan 47º. tan 12°tan 600

1.	.Q-19 Prove that : 3 cos 68º.cosec22°43º. tan 47º. tan 12°tan 600 tan 780-6-V3
Answer» 3 cos 68. cosec 22 - 1/2 tan 43 . tan 47. tan 12. tan 60 . tan 78 ⇒3 sin 22 . cosec 22 - 1/2 cot 47 .tan 47 .cot 78 .√3 . tan 78 (since cos 68 = sin 22, tan 43 = cot 47,tan 12 = cot 78 and tan 60 =√3) ⇒3 * 1/cosec 22 * cosec 22 - 1/2 cot 47 * 1/cot 47 . cot 78 . 1/cot 78 *√3 ⇒3 -√3/2 ⇒(6 -√3)/ is the answer 2

.Q-19 Prove that : 3 cos 68º.cosec22°43º. tan 47º. tan 12°tan 600 tan 780-6-V3

Answer»

3 cos 68. cosec 22 - 1/2 tan 43 . tan 47. tan 12. tan 60 . tan 78

⇒3 sin 22 . cosec 22 - 1/2 cot 47 .tan 47 .cot 78 .√3 . tan 78

(since cos 68 = sin 22, tan 43 = cot 47,tan 12 = cot 78 and tan 60 =√3)

⇒3 * 1/cosec 22 * cosec 22 - 1/2 cot 47 * 1/cot 47 . cot 78 . 1/cot 78 *√3

⇒3 -√3/2

⇒(6 -√3)/ is the answer 2