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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: andy456 on November 04, 2010, 10:38:09 am

Title: Diff Question
Post by: andy456 on November 04, 2010, 10:38:09 am: Just wanna check what I got because I dont have answers and my calc is dead.

Find d $y= (x^2 - 2x)e^x$ /dx

I got $e^x(x^2-2)$

Hence find antiderivative of $x^2e^x$

Is it $(x^2-2x)e^x + \int2e^x dx$
Thanks
Title: Re: Diff Question
Post by: costa94 on November 04, 2010, 10:41:23 am: you get integral of x^2 * e^x - 2x * e^x = integral x^2 * e^x - integral 2x * e^x = (x^2 - 2x)*e^x
so re arrange it
Title: Re: Diff Question
Post by: TrueTears on November 04, 2010, 10:16:59 pm: Quote from: andy456 on November 04, 2010, 10:38:09 am
Just wanna check what I got because I dont have answers and my calc is dead.

Find d $y= (x^2 - 2x)e^x$ /dx

I got $e^x(x^2-2)$

Hence find antiderivative of $x^2e^x$

Is it $(x^2-2x)e^x + \int2e^x dx$
Thanks
yes it's correct :)