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Evaluate `int(dx)/((1-x^(2))sqrt(1-x^(2))).` |
Answer» ` I=int(dx)/((1-x^(2))sqrt(1-x^(2)))` Put `x="sin"theta` `:. I=int("cos"theta d theta)/((1+sin^(2)theta)(cos theta))` `=int(d theta)/(1+sin^(2)theta)` `=int("cosec"^(2)theta d theta)/(2+cot^(2)theta)` Put `cot theta=t` `:. -"cosec"^(2)theta d theta=dt` `:. I=int(-dt)/(2+t^(2))` `=-(1)/(sqrt(2))"tan"^(-1)(t)/(sqrt(2))+c` `= -(1)/(sqrt(2))"tan"^(-1)(cot theta)/(sqrt(2))+c` `=-(1)/(sqrt(2))"tan"^(-1)(sqrt(1-x^(2)))/(sqrt(2x))+c` |
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