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(tan15° +1)/(tan15°-1)
=(sin15°+cos15°)/(sin15°-cos15°)
let
(sin15°+cos15°)/(sin15°-cos15°) = x
(1+ sin30°)/(1-sin30°) =x^2
x^2 = 3
x=-√3
(tan15° +1)/(tan15°-1) =-√3
=(sin15°+cos15°)/(sin15°-cos15°)
let
(sin15°+cos15°)/(sin15°-cos15°) = x
(1+ sin30°)/(1-sin30°) =x^2
x^2 = 3
x=-√3
(tan15° +1)/(tan15°-1) =-√3
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(tan15° +1)/(tan15°-1)
=(sin15°/cos15° +1)/ (sin15°/cos15° -1)
=(sin15°+cos15°)/(sin15°-cos15°)
let
(sin15°+cos15°)/(sin15°-cos15°) = x
(sin15°+cos15°)^2/(sin15°-cos15°)^2 = x^2
(1+ 2sin15°.cos15°)/(1- 2sin15°.cos15°)=x^2
(1+ sin30°)/(1-sin30°) =x^2
x^2 = 3
x=-√3
(tan15° +1)/(tan15°-1) =x =-√3
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