If $\frac{cosecθ+cotθ}{cosecθ-cotθ}=7,$ then the value of $\frac{4sin^2θ+5}{4sin^2θ-1}$ is : |
3 15 9 12 |
9 |
\(\frac{cosecθ+ cotθ}{cosecθ - cotθ}\) = 7 \(\frac{1+ cosθ}{1 - cosθ}\) = 7 1+ cosθ = 7 - 7cosθ 8cosθ = 6 cosθ = \(\frac{3}{4}\) { we know, cosθ = \(\frac{B}{H}\) } By using pythagoras theorem, P² + B² = H² P² + 3² = 4² P = \(\sqrt {7 }\) Now, \(\frac{4 sin²θ + 5 }{4sin²θ - 1 }\) = \(\frac{4 × 7/16 + 5 }{4× 7/16 - 1 }\) = 9 |