symbol help

Discussion in 'Homework Help' started by amilton542, Dec 30, 2010.

  1. amilton542

    Thread Starter Active Member

    Nov 13, 2010
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    some of the formulas ive been looking at are containing symbols i dont understand and there not saying what they mean :confused:
    here are the symbols i dont get:

    Ʃ - ive also been coming across this with a ∞ above it, does this mean infinite?
    ∫ - i think this means inertia but what does inertia mean? ive also seen three of these in a row one after the other, sometimes with a circle in the middle, i think that means at any point.

    . - i presume the full stop is multiply ?
     
  2. beenthere

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  3. shteii01

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  4. Georacer

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    Σ is for sum. It usually comes with a variable term that is summed over and over.
    For example \Sigma _{\tiny{i=1}} ^{\tiny4} i=10

    \int is for integration. Multiple integration signs mean integration in more than one dimension. A circle denotes integration over a closed line.
    For example \int _0 ^5 x\ dx=\left[ x^2 \right] _0 ^5=25

    As for the dot, it depends on its position in the expression. Can you be more specific?
     
  5. amilton542

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    thanks guys it doesnt look as scary anymore. ok i can be more specific with the . , for e.g there will be an upside down triangle . B = 0. i think i need to work on my maths, i been reading a book on magnetism and magnetic materials and its all maths way beyond me
     
  6. Papabravo

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    The upside down triangle is called "del" and it is a differential operator. See the following article:

    http://en.wikipedia.org/wiki/Del

    The interpretation depends on the thing it is applied to. This stuff isn't easy and a quick review is unlikely to be sufficient if you've never seen it before.
     
    Last edited: Dec 30, 2010
  7. amilton542

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    ok thanks, these wikipedia print outs has provided me with more than enough for today. how long will this take to grasp to understand properly?because this does seem hard. i do about 15-20 hours a week self direct research
     
  8. shteii01

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    The sum is easy, it is basically an abbreviation.

    Integral is more complex, but there are formulas that let you go from the integral to integral solution, basically someone in the past 300 years solved that particular type of integral, all you have to do is setup the integral, then look up in the list which type your integral match: http://en.wikipedia.org/wiki/Lists_of_integrals
     
  9. amilton542

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    are there any youtube lectures on this? i dont no what to type to find what im looking for
     
  10. shteii01

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  11. Papabravo

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    It took me about four semesters of math and physics courses to really grab onto what was happening with calculus, vectors, and vector differential operators. That is about halfway to an undergraduate degree in Electrical Engineering
     
  12. bertus

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  13. Wendy

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    A lot of this deals with calculus. Many electronics circuits operate around the math of calculus, so it is there. This isn't as bad as it sounds though, once you understand the basics most of the formula are already developed.
     
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