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Homework Help: Area in shades region (Matlab)

  1. Aug 11, 2014 #1


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    Gold Member

    ImageUploadedByPhysics Forums1407795886.518929.jpg
    This is a part matlab and part math question. I know for the shaded region, I would usually do
    ##A_{shaded} = \int_{inter(2)}^{inter(3)} f_{1}(x) \mathrm{d}x - \int_{inter(2)}^{inter(3)} f_{2}(x) \mathrm{d}x##

    However, since it appears they want the function handle to be just one line, am I allowed to do

    Code (Text):
    fh = @(x) -0.1*x.^3 - 0.5*x.^2 - 2.2*x + 9
    Since I can't make two integrals and just subtract them?

    In other words, would it be correct to say
    ##A_{shaded} = \int_{inter(2)}^{inter(3)} (f_{1}(x)-f_{2}(x)) \mathrm{d}x##?
    Last edited: Aug 11, 2014
  2. jcsd
  3. Aug 12, 2014 #2


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    Science Advisor

    Yes, of course, that's correct. One of the first things you should learn about integrals is that they are "linear": [tex]\int_a^b (\alpha f+ \beta g) dx= \alpha\int_a^b f dx+ \beta \int_a^b g dx[/tex]
    Last edited by a moderator: Aug 12, 2014
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