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Calculate a area in a graph.

  1. Mar 11, 2014 #1
    Calculate area D=(x,y): -1≤X≤0 0≤Y≤ X²+4x+5

    I started with dA=f(x) dx
    ∫f(Y=x²+4x+5) [F(x) x^3/3 + 2X²+5X] higer limit 0 lower limit -1

    F(a)-F(b) = -3,5

    I dont get this ... ??
    What am i missing?

  2. jcsd
  3. Mar 11, 2014 #2

    Ray Vickson

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    Science Advisor
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    1) For ##F(x) = \frac{1}{3}x^3 + 2 x^2 + 5x## we have ##F(-1) \neq -3.5##.
    2) ##\text{Area} = F(0) - F(-1)##, not the other way round.
  4. Mar 11, 2014 #3


    Staff: Mentor

    Also, even if F(-1) happened to be equal to -3.5 (it isn't), 0 - (-3.5) ≠ -3.5.

    One more thing - questions about derivatives or integrals should be posted in the Calculus & Beyond section, not in the Precalculus section.
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