Question

if (1+cos theta)(1-cos theta).cosec^2 theta=k. find value of k

Answer 1

Solution:-

( 1 + cosA) ( 1 - Cos A) × Cosec^2A = k

=> ( 1 - Cos^2A) × Cosec^2A

=> Sin^2A × Cosec^2A

=> Sin^2A × 1/ Sin^2A

=> 1.

Answer 2

k=1
because
we know that
cosec^2 theta=1/sin^2theta

then (1+cos theta)(1-cos theta).cosec^2=
(1-cos^2 theta).1/sin^2 theta

we know that
(1-cos^2 theta)=sin^2 theta

then sin^2 theta / sin^2 theta=1


hope this ans helps you
thanks