Question

cosa×√1+cot²a=√cosec²a-1​

Answer 1

$cosa \sqrt{1 + {cot}^{2}a } \\ = cosa \sqrt{ {cosec}^{2} a} \\ = cosa \: coseca \\ = \frac{cosa}{sina} \\ = cota \\ = \sqrt{ {cot}^{2}a } \\ = \sqrt{ {cosec}^{2} a - 1}$