#finding area between two functions at interval

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iron sun
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I got 22 but the guy in the video got 14. He doesnt show his working so i dont understand where i went wrong here?

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sweet acornBOT
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stable gale
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how do u not know that omg

iron sun
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just so you see the question more clearly, the question was:
find the area between y=3x^2+5 and y=-x+3 at interval 0 to 2

iron sun
stable gale
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jk

candid bronze
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A) When you do $\int ax + b dx$ you have to distribute evenly to get $c \int \frac{ax}{c} + \frac{b}{c} dx$

plain crestBOT
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r•eⁱˣ = r•cos(x) + ri•sin(x)

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candid bronze
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You also do a few math mistakes, like doing 2^2 instead of 2^3 on line four

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Try reintegrating but not distributing out any terms

loud grove
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,w int (3x^2+5) - (-x+3), x=0..2

plain crestBOT
loud grove
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a general technique to find out a mistake is by a "binary search" technique.
if n-th line is mistaken, then look at n/2-th line:

  • if it's good, then look at the lower half
  • if it's bad, then look at the upper half
    to do the testing, i suggest that you bring an examination board approved scientific calculator with numerical integration.
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here's an example showing a model that i used for my secondary school

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disclaimer: i'm not affiliated with CASIO

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the button that i circled with yellow marker provides the numerical integration functionality, so that you can get an approximate numerical answer for your definite integral

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the wolfram alpha is for quick self-checking at home, and the calculator technique is for exam/tests.

iron sun
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alright thanks guys

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looking back it was kind of a stupid question 😅

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