So I’m gearing up to take a calculus 1 exam, and this question is on the sample test. My initial thought was that since we are looking for F(9), and F(x) is an antiderivative of f(x), I can just use the integral of the equation of f(x) at 9, which is f(x) = -2x/3 + 5, which, when integrated, becomes -x^2/3 + 5x + 2 (C = 2 because F(0) = 2). Thing is, though, that won’t give me any of the answers listed. And even after taking the integral of all of the equations of f(x), I still have no idea how to produce any of the answers in the multiple choice.

I’m super stumped on this one. Any help would be welcome!

  • @Swedishfish12@lemmy.world
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    41 year ago

    This is a question designed to test your understanding of the underlying concepts as opposed to just being able to mechanically manipulate the functions.

    If you have a value of the anti derivative F(x) at some point x=a and you want to find F(x) at x=b, you can find it with the equation F(b) = F(a) + <the area under f(x) between x=a and x=b>.

    This problem gives you F(a) where a=0 and gives you f(x) between 0 and 9.

    • @buchoOP
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      11 year ago

      Thanks! This has been incredibly helpful. :)