Solve for $θ : 3 cosec θ + 4sin θ - 4 \sqrt{3} = 0, $ where θ is an acute angle.
Answer & explanation
Correct answer: option 3
3 cosecθ + 4 sinθ - 4√3 = 0
3 × \(\frac{1}{sin θ}\) + 4 sinθ - 4√3 = 0
3 + 4 sin²θ - 4√3 sinθ = 0
4 sin²θ - 2√3 sinθ- 2√3 sinθ + 3 = 0
2sinθ ( 2sinθ - √3 ) - 1 ( 2sinθ - √3 ) = 0
( 2sinθ - √3 ) ( 2sinθ - 1 ) = 0
Either 2sinθ - √3 = 0 OR 2sinθ - 1 = 0
2sinθ - 1 = 0 is not possible because θ is an acute angle triangle.
So, 2sinθ - √3 = 0
sinθ = \(\frac{√3}{2}\)
{ we know, sin60º = \(\frac{√3}{2}\) }
so, θ = 60º