The least value of $8cosec^2\theta + 25 sin^2 \theta $ is :

$30\sqrt{2}$ $40\sqrt{2}$ $10\sqrt{2}$ $20\sqrt{2}$

$20\sqrt{2}$

a cosec²θ + b sin²θ minimum value for it = 2\(\sqrt {ab }\) 8 cosec²θ + 25 sin²θ Minimum value = 2\(\sqrt {8 × 25 }\) = 20\(\sqrt {2 }\)