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Math Help - Explain me why ...

  1. #1
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    Explain me why ...

    Can you explain me how this is solved in this way.

    f(x, y) = x + 2y + 3.

    if x = 3 and y = 1 then f(x, y) = 3 + 2 + 3 = 8. We write f(3, 1) = 8.

    I just want to know why x=3 and y=1

    HOW ARE THEY SOLVED ?
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  2. #2
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    Hello SmallMan
    Quote Originally Posted by SmallMan View Post
    Can you explain me how this is solved in this way.

    f(x, y) = x + 2y + 3.

    if x = 3 and y = 1 then f(x, y) = 3 + 2 + 3 = 8. We write f(3, 1) = 8.

    I just want to know why x=3 and y=1

    HOW ARE THEY SOLVED ?
    No reason - this is just an example, that's all. f(3,1) = 8.

    You might equally well say, when x = 2 and y = 0, f(x,y) = 2+0+3=5. So f(2,0) = 5.

    It's just showing you how to use the function notation when it's a function of two variables.

    Grandad
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  3. #3
    A riddle wrapped in an enigma
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    Quote Originally Posted by SmallMan View Post
    Can you explain me how this is solved in this way.

    f(x, y) = x + 2y + 3.

    if x = 3 and y = 1 then f(x, y) = 3 + 2 + 3 = 8. We write f(3, 1) = 8.

    I just want to know why x=3 and y=1

    HOW ARE THEY SOLVED ?
    Hi SmallMan,

    What is the context of your function? This looks like a min/max function in linear programming. x and y would be determined by the vertices of the feasible region. Is that what this is?

    It looks a though x = 3 and y = 1 were given to you up front, and you just substituted them into the function. Can you elaborate a little more?
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  4. #4
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    Ok i understand. Anyway - i will be inerting here all my question concerning this topic.

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