Practicing Success
If $\cot \theta+\tan \theta=2 \sec \theta, 0^{\circ}<\theta<90^{\circ}$, then the value of $\frac{\tan 2 \theta-\sec \theta}{\cot 2 \theta+{cosec} \theta}$. |
$\frac{2 \sqrt{3}-1}{5}$ $\frac{3-\sqrt{2}}{5}$ $\frac{2 \sqrt{3}-1}{11}$ $\frac{3-\sqrt{2}}{11}$ |
$\frac{2 \sqrt{3}-1}{11}$ |
cot θ + tan θ = 2 sec θ \(\frac{cosθ}{sinθ}\) + \(\frac{sinθ}{cosθ}\) = 2 . \(\frac{1}{cosθ}\) \(\frac{cos²θ + sin²θ}{sinθcosθ}\) = 2 . \(\frac{1}{cosθ}\) { cos²θ + sin²θ = 1 } \(\frac{1}{sinθ}\) = 2 sinθ = \(\frac{1}{2}\) { we know, sin 30º = \(\frac{1}{2}\) } So, θ = 30º Now, \(\frac{tan2θ - secθ}{cot2θ + cosecθ}\) = \(\frac{tan60º - sec30º}{cot60º + cosec30º}\) = \(\frac{ √3 - 2/√3 }{1/√3 + 2}\) = \(\frac{ 1 }{ 2√3 + 1 }\) = \(\frac{ 1 }{ 2√3 + 1 }\) × \(\frac{ 2√3 - 1 }{ 2√3 - 1 }\) = \(\frac{ 2√3 - 1 }{ 11}\) |