Establish the identity 1sin theta1 sin theta tan theta sec
Establish the identity. 1-sin theta/1+ sin theta = (tan theta - sec theta)^2 Starting with the right side, which shows the key steps in establishing the identity? (tan theta - sec theta)^2 = tan^2 - sec^2 theta = (sin theta - 1)^2/1-sin^2 theta = 1-sin theta/1+sin theta (tan theta - sec theta)^2 = tan^2 - sec^2 theta = (sin theta - 1)^2/1-cos^2 theta = 1-sin theta/1+sin theta (tan theta - sec theta)^2 - sin^2 theta/coss^2 theta - 2 sin theta/cos^2 theta + 1/cos^2 theta = (sin theta-1)^2/1- cos^2 theta = 1 - sin theta/1 + sin theta (tan theta - sec theta)^2 - sin^2 theta/coss^2 theta - 2 sin theta/cos^2 theta + 1/cos^2 theta = (sin theta-1)^2/1- sin^2 theta = 1 - sin theta/1 + sin theta
Solution
(1-sin theta)/(1+sin theta)= (sec theta - tan theta)2
Starting with the right side
(tan theta - sec theta)2
sec theta=1/cos theta and tan theta= sin theta/cos theta
(sin theta/cos theta - 1/cos theta)2 = (sin theta-1)2/cos2theta
= (sin theta -1)2/(1-sin2theta)= (1-sin theta)2/(1-sin theta)(1+sin theta)
=(1-sin theta)/(1+sin theta)
The correct option is D
