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Home > Differential Equations
Differentiate the following with respect of x:
y = tan-1 1 + x - 1 - x1 + x + 1 - x
Let x = cos 2θ ⇒ θ = 12 cos-1 x .................(1)∴1 + x = 1 + cos2θ = 1 + 2cos2θ -1 = 2 cosθ 1 - x = 1 - cos2θ = 1 - 1 - 2sin2θ = 2 sinθLet y= tan-1 1 + x - 1 - x1 + x + 1 - x = tan-1 2 cosθ - 2 sinθ2 cosθ + 2 sinθ = tan-11 - tanθ1 + tanθ = tan-1 tan π4 - θ = π4 - θ = π4 - 12cos-1x .........From(1)∴dydx = -12-11 - x2 = 12 1 - x2
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