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What's the difference between magnitude and pythagorean's theorem

  1. Mar 30, 2010 #1
    and what are the concepts of magnitudes..and how do we apply that in real life situations.
  2. jcsd
  3. Mar 30, 2010 #2
    Magnitude just means "size" or "bigness" - so it can be used in many different situations.

    Pythagoras' theorem just helps us to calculate magnitude in some situations:

    If you imagine a graph with x going across and y going upwards, you can draw a line from the centre (where the axes cross at 0,0) to any point you like... for example the point 4,3 (x=4, y=3).

    So if you then draw another line along the x axis to 4, and another up to the end of your line, you have drawn a triangle, and you can use pythagoras to find the length (the magnitude) of your line

    magnitude2 = x2 + y2

    = 42 + 32

    = 16 + 9 = 25
    so magnitude in this case is sqrt (25) = 5

    you could use this to calculate the size of a piece of wood you would need on a gate, or something much more advanced.

    hope this helps,
  4. Mar 30, 2010 #3
    Magnitude (in terms of vectors) is simply an application of the Pythagorean theorem. It's more of a subcategory than a side-by-side comparison.
  5. Mar 31, 2010 #4
    ah..so meaning magnitude is the application of pythagorean theorem...ahhh... makes sense..

    but how about resultant from magnitude??what is thier differences??can you please help me?..im so confused right now..
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