Practicing Success
If $\cot \theta=\frac{15}{8}, \theta$ is an acute angle, then find the value of $\frac{(1-\cos \theta)(2+2 \cos \theta)}{(2-2 \sin \theta)(1+\sin \theta)}$. |
$\frac{225}{64}$ $\frac{64}{225}$ $\frac{16}{15}$ $\frac{8}{15}$ |
$\frac{64}{225}$ |
cotθ = \(\frac{15}{8}\) { we know, cotA = \(\frac{B}{P}\) } By using pythagoras theorem, P² + B² = H² 8² + 15² = H² H = 17 Now, \(\frac{ (1 - cosθ). (2+2cosθ) }{(2-2sinθ). (1 + sinθ ) }\) = \(\frac{ (1 - cosθ). (1+cosθ) }{(1-sinθ). (1 + sinθ ) }\) = \(\frac{ (1 - cos²θ) }{(1-sin²θ) }\) { we know, sin²θ + cos²θ = 1 } = \(\frac{ (sin²θ) }{(cos²θ) }\) = tan²θ = \(\frac{B²}{P²}\) = \(\frac{8²}{15²}\) = \(\frac{64}{225}\) |