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JEE MainMathematicsEasyIndefinite integration

∫dx(1+x)+x=\int\frac{dx}{\sqrt{(1 + x)} + \sqrt{x}} =

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Rationalising the denominator, we have
∫dx(1+x)+x=∫{(1+x)−x}{(1+x)+x}{(1+x)−x}dx\int\frac{dx}{\sqrt{(1 + x)} + \sqrt{x}} = \int\frac{\{\sqrt{(1 + x)} - \sqrt{x}\}}{\{\sqrt{(1 + x)} + \sqrt{x}\}\{\sqrt{(1 + x)} - \sqrt{x}\}}dx
=∫{(1+x)−x}(1+x)−xdx=∫[(1+x)−x]dx= \int\frac{\{\sqrt{(1 + x)} - \sqrt{x}\}}{(1 + x) - x}dx = \int\lbrack\sqrt{(1 + x)} - \sqrt{x}\rbrack dx
=23(1+x)32−23x32+c= \frac{2}{3}(1 + x)^{\frac{3}{2}} - \frac{2}{3}x^{\frac{3}{2}} + c

Source: Grass-G / M-12 Mathematics Paper 2 Nov.docx

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