Solve for $θ : 3 cosec θ + 4sin θ - 4 \sqrt{3} = 0, $ where θ is an acute angle. |
45° 30° 60° 15° |
60° |
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 |