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Algebra Vocabulary Numbers and Variables - College Algebra

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    In the past few minutes we've touched on a
    lot of concepts that are going to play a
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    really central role in the rest of the
    course and really in all math going
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    forwards from here. So I would like to do
    a review of the algebra vocabulary that
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    we've covered so far. I think it's
    actually going to amaze you how much we've
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    already gone over in a pretty short amount
    of time. So first thing first, we have
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    numbers, as one might expect in math. So
    what are some examples of numbers? Well,
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    we could have any number of things. So
    like we learned in the very beginning of
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    this course, they're all different kinds
    of numbers. Some that are pretty simple
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    and we use all the time, like 0 or 1 or
    46, and some that are a little bit more
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    special, like the root of 2 or pi. Then in
    contrast to numbers, we also learned about
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    variables. So, here we have all different
    kinds of symbols, we have some letters, we
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    have some sillier things like hearts and
    smiley faces, we got some greek letters.
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    But regardless of what we write variables
    as they all have the same purpose, as we
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    learned earlier. Variables are symbols
    that we use in equations and expressions
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    that serve as slots into which we can plug
    other numbers to make our expressions take
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    on different values. So comparing numbers
    and variables, numbers have fixed values.
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    They inherently show certain quantities.
    Variables, however, don't show outright
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    what they stand for, they're just place
    holders into which we can insert different
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    numbers. One thing to take note of when
    we're looking at what's inside each of
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    these circles is that we actually have a
    symbol on the number side. That's this pi
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    right here. Since pi is an irrational
    number, it extends for an infinite number
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    of decimal points. Now, it took me an
    awfully long time to write all of this
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    out. So if I were to write even more, that
    would take me even longer. To make our
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    lives much more simple, we give this
    infinitely long number a special name,
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    which is pi. A similar thing happens when
    we write square roots. We have a number,
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    2, right here but we also have a square
    root sign over it. Since the root of 2 is
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    also an irrational number the square root
    sign is just another way of taking a
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    shortcut to not have to write out an
    infinite number of decimals. So bottom
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    line, when you see symbols, they're almost
    always variables. They'll be certain
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    cases. Which you'll become well acquainted
    with when you see things like pi or like a
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    square root sign that are symbols of some
    sort but represent numbers.
Cím:
Algebra Vocabulary Numbers and Variables - College Algebra
Video Language:
English
Team:
Udacity
Projekt:
MA008 - College Algebra
Duration:
02:16

English subtitles

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