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Find the value of cos x/2- tan x/2 is |
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Answer» cotx/2 - tanx/2 Take x/2 = a for easy notation = cosa / sina - sina/cosa = cos2a - sin2a / sin a cosa Multiply by 2 . = 2 ( cos2a) / 2sina cosa = 2cos2a / sin2a = 2 cot 2a = 2 cot 2 ( x/2) = 2 cot x. So, the value of cotx/2 - tanx/2 is 2 cot x. |
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