Question

If 5θ and 4θ are acute angles satisfying sin 5θ = cos 4θ, then 2 sin 3θ – √3 tan 4θ is equal to
A. 1
B. 0
C. - 1
D. 1 + √3

Answer 1

Answer:

....................

Answer 2

B. 0

Step-by-step explanation:

Given: sin 5θ = cos 4θ

Find: 2 sin 3θ – √3 tan 3θ  

Solution:

 sin 5θ = cos 4θ

 sin 5θ = sin (90-4θ) °

 5θ = 90°-4θ  

 9θ = 90°

Therefore θ = 10 °

So 2 sin 3θ – √3 tan 3θ = 2 Sin 30° - √3 tan 30 °

= 2 * 1/2 - √3 * 1/√3

= 1 - 1  

= 0

Option B is the answer.

Note: Error in question. It should be 2 sin 3θ – √3 tan 3θ, not tan 4θ.