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Expert: Steve Holleran - 9/29/2007


Question
I cannot do this integration could you please help
=INTEGRAL(2x((1-x^2)^(1/2))dx        
it would be great if you could help

Answer
Hi Mark,

Here, call 1-x^2 = u.

Then du = -2x * dx, so in the integral, multiply inside and outside by -1:

  = -1 * INT[ -2x * dx * (1-x^2)^1/2]

which becomes, under the substitution,

  = -1 * INT[ u^1/2 * du] = -1 * u^3/2 / 3/2  + C

 = -2/3 * (1-x^2)^3/2 + C.

Hope this helps.

I'm working on the other one you sent me--its harder.

Steve

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Steve Holleran

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I can help with all math questions from basic math to Calculus. Whether it`s consumer questions, or questions from high school or college students, I have probably dealt with it at some time in my career.

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33 years teaching experience in NJ public schools

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B.S. Mathematics : Wake Forest University 1972 M.S. Mathematics : Monmouth University 1981

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