Practicing Success
If sinθ = $\frac{12}{13}, 0 < θ < 90^o, $ then $\frac{sin^2θ-cos^2θ}{2sinθ.cosθ}×\frac{1}{tan^2θ}$ = ____________. |
$\frac{295}{3456}$ $\frac{590}{3542}$ $\frac{695}{3542}$ $\frac{595}{3456}$ |
$\frac{595}{3456}$ |
sinθ = \(\frac{12}{13}\) { we know, sinθ = \(\frac{P}{H}\) } By using pythagoras theorem, P² + B² = H² 12² + B² = 13² B = 5 Now, \(\frac{ sin²θ - cos²θ }{2sinθ.cosθ}\) × \(\frac{1}{tan²θ}\) = \(\frac{ P² - B² }{2P.B}\)× \(\frac{B²}{P²}\) = \(\frac{ 12² - 5² }{2× 12×5 }\)× \(\frac{5²}{12²}\) = \(\frac{ 144 - 25 }{120 }\)× \(\frac{25}{144}\) = \(\frac{ 2975 }{17280 }\) = \(\frac{ 595 }{ 3456 }\) |