Question

Hey !!

Question :-

Choose the correct option from the options given below !
If cos ( α/3 ) = 1/2 find the value of sin α .

OPTION A : 1
OPTION B : 0
OPTION C : -1
OPTION D : 0.5

Also give me any formula that you used in the above problem :) It will help Me !

DON'T DARE TO SPAM !

Answer 1

Answer:

Option A -- 1

Step-by-step explanation:

If you wanna see Explanation see the attachment

Answer 2

Answer:

Option(B)

Step-by-step explanation:

Given: cosα = (1/2)

∴ cos 3α = 4 cos³α - 3 cosα

⇒ cosα = 4 cos³(α/3) - 3 cos(α/3)

⇒ cosα = 4(1/2)³ - 3(1/2)

⇒ cosα = 4(1/8) - (3/2)

⇒ cosα = (1/2) - (3/2)

⇒ cosα = -1

Now,

∴ Sin²α = 1 - cos²α

           = 1 - (-1)²

           = 0

Therefore, sinα = 0.

Hope it helps!