if tan theta=4/3 show: root 1-sin theta/1+sin theta+ root 1+sin theta/1-sin theta=10/3
Answers
EXPLANATION:
tan theta = 4/3 = opposite side/adjacent side
By writing the given data on the opposite and adjacent side of a right-angled triangle,
By the Pythagorus theorem,
Hypotenuse =root (4^2+3^2)
sin theta = opposite side/hypotenuse = 4/5
cos theta = adjacent side/hypotenuse = 3/5
NOW,
L.H.S= root {1-sin theta}/{1+sin theta} + root{1+sin theta}/{1-sin theta}
= root{(1-sin theta)(1-sin theta)} / {(1+sin theta)(1-sin theta)} + root{(1+sin theta)(1+sin theta)} / {(1-sin theta)(1+sin theta)}
(Taking conjugate)
= root{(1-sin theta)^{2}} / {(1+sin theta)(1-sin theta)} + root{(1+sin theta)^{2}} / {(1-sin theta)(1+sin theta)}
= root {(1-sin theta)^{2}} / {(1^{2}-sin^{2} theta)} + root{(1+sin theta)^{2}} / {(1^{2}-sin^{2} theta)}
(1- sin^{2} theta = cos^{2} theta)
= root{(1-sin theta)^{2}} / {(cos^{2} theta)} + root{(1+sin theta)^{2}} / {(cos^{2} theta)}
= {1- sin theta} / {cos theta} + {1+sin theta} / {cos theta}
= {1- sin theta + 1 + sin theta} / {cos theta}
(Taking L.C.M.)
= {2} / {cos theta}
= {2} / {3/5}
= 10/3
= R.H.S.
HENCE PROVED.
Hope this helped..