WEBVTT
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Okay, so we are discussing quadratic functions, and
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we need to write the standard form of the equation
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of parabola that has the Vertex for negative one and
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passes through the 0.23 Okay, so let's use a
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graph to help us for a second. So we're
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told that the Vertex, which is h comma K
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, is four negative one. Okay, so right
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now the formula is y equals a times X minus
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h squared, plus K. So we know everything
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, except we don't know a yet, so we'll
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come back to this graph in a minute. All
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right, So we have Why is equal toe a
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X minus? H squared plus K and with the
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Vertex were given we have wise equal to a X
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minus or X plus four. Excuse me. No
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, Sorry. X minus four squared in the minus
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one. Okay, so now we need to find
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what a is. So we're given the 0.2 comma
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three. So why is three and X is too
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? So we have three is equal to a tu
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minus four is negative. Two negative. Two squared
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is four. Oh, this is a minus one
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. Okay, So, adding one to this side
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is for is equal to four A. Therefore,
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A is equal to one. So our formula is
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X minus four squared minus one and and we can
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see from our graph that the 0.2 comma three is
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on the graph.