Question #24c10

1 Answer
Feb 9, 2017

Explained below

Explanation:

In the numerator on the left side add and subtract 1 as,

1+tan^2 theta +cos^2 theta -1

or, 1+tan^2 theta -( 1-cos^2 theta)

or, sec^2 theta - sin^2 theta

or, 1/(cos^2 theta) - sin^2 theta. Now factorise it,

(1/cos theta - sin theta)(1/cos theta + sin theta)

The factor (1/ cos theta + sin theta) would get cancelled out with the denominator, leaving with the factor 1/cos theta - sin theta= RHS