Thread: math function (order of operations)

  1. 02-02-2012 #1
    slee8251
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    math function (order of operations)

    Can someone please explain the difference between the two, given the same radius? They produce different results. Thanks in advance

    Code:
    #define PI 3.1416
volume = (4*PI/3)*pow(radius,3);
volume = (4/3) * PI * pow(radius,3);
  2. 02-02-2012 #2
    laserlight
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    Hint: integer division.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way
  3. 02-02-2012 #3
    slee8251
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    ahh okay thanks.

    so if you do (4.0/3.0) it should work, right?
  4. 02-03-2012 #4
    nonoob
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    Yes. At least one of the constants needs to be floating point representation so that the compiler uses floating point math.
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