If $3 \sin ^2 \theta+4 \cos \theta-4=0,0^{\circ}<\theta<90^{\circ}$, then the value of $\left(cosec^2 \theta+\cot ^2 \theta\right)$ is |
$\frac{5}{4}$ $\frac{25}{3}$ $\frac{4}{3}$ $\frac{17}{9}$ |
$\frac{5}{4}$ |
3 sin2θ + 4 cosθ - 4 = 0 3 ( 1 - cos2θ) + 4 cosθ - 4 = 0 3cos2θ - 4 cosθ + 1 = 0 on solving , cosθ = \(\frac{1}{3}\) By using pythagoras theorem , P2 + B2 = H2 P2 + 12 = 32 P = 2√2 Now , ( cosec2θ + cot2θ) = (\(\frac{3}{2√2}\))2 + (\(\frac{1}{2√2}\))2 = \(\frac{9}{8}\) + \(\frac{1}{8}\) = \(\frac{5}{4}\) |