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https:/.../Polynomial+from+linear+factors.mp4

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    These are the five linear
    factors that the problem gave us
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    for this polynomial.
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    It wanted us to figure out
    a few things.
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    It wanted us to figure out
    what the factored form
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    of the polynomial would be
    and it wanted us to figure out
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    what the x-intercepts of the
    polynomial would be.
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    So if we look at these
    linear factors,
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    we have y = x+1,
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    y = -x-2,
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    y = 2x-5,
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    y = x+1/2-√3,
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    and y = x+1/2+√3.
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    Those were given to us
    in the original problem.
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    And are graphed on this graph here.
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    So how do we find the x-intercepts
    of these linear graphs?
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    Well we simply do it,
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    by setting each one equal
    to zero.
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    Now, you might notice
    that on desmos it will give
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    you the decimal equivalent,
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    but you can see over here
    to the left,
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    it's -1/2+√3,
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    and then -1/2-√3.
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    So it's shown over here
    in its exact form,
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    and then it's shown on
    here in this decimal equivalency.
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    So we have these five
    x-intercepts now.
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    Here's the deal,
    remember we just learned
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    that the x-intercepts
    of the linear factors
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    are the same x-intercepts
    as the actual graph.
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    So if we take these five
    linear factors and we multiply
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    them altogether to get our function,
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    which is so big I have to even
    make this wider for a sec so
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    we can look at it.
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    So we took the first linear function
    times the second linear function
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    times the third linear function
    times the fourth linear function,
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    times the fifth linear function.
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    So it's the product of all those
    that were given.
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    Let me make this smaller
    again so you can see the graph.
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    That's what I want you to
    be able to see.
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    If that is the factored form
    of the polynomial expression.
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    So that was one of the questions
    that was asked.
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    I'll show it to you again
    in just a second but we want
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    to test it on here and make sure
    that our x-intercept
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    of our linear is the same
    x-intercepts as our polynomial.
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    And you can see that it is.
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    I'm going to zoom out a little
    bit because--
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    I'll zoom back in so you can
    get closer,
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    but you can see the um--
    there we go,
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    the local, there we go,
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    the local maximum and
    the local minimum.
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    So that you can see how that
    all plays in there.
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    It's much um...more increasing
    and decreasing as in our
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    last example.
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    So lets go back in again
    so you can see the closer.
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    So you can see exactly the
    same spots that was the
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    x-intercepts of the linear
    are now the x-intercepts
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    of our polynomial.
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    And one more time,
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    allow me to put the
    equation on the screen
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    so that you can see the
    factored form of the polynomial.
Title:
https:/.../Polynomial+from+linear+factors.mp4
Video Language:
English
Duration:
03:27

English subtitles

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