Question

Sec(-1680)Sin(330)=1

Answer 1

Hi Friend !!!

Here is ur answer !!!

sec(1680)sin330

= sec(1440+240)sin(360-30)

= sec240sin-30

= - sec(270-30)sin30

= cosec 30 sin30

= sin30/sin30

= 1


Hope it helps u :-)

Answer 2

Answer:

The proof is explained step-wise below :

Step-by-step explanation:

To Prove : sec(-1680) × sin(330) = 1

Proof : Taking L.H.S

sec(-1680) × sin(330)

⇒ sec(1680) × sin(330) (∵ sec(-α) = sec α)

⇒ sec (1440 + 240) × sin(360 - 30)

⇒ -sec(240) × -sin 30°

⇒ sec(270 - 30) × sin 30°

⇒ cosec 30° × sin 30°

⇒ 1

= R.H.S.

Hence Proved