WEBVTT
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What is the midline of π¦ equals five over four cos of ππ₯ over seven minus five plus 12?
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Letβs think about a few things.
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The midline is the horizontal centre line about which the function oscillates above and below.
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The midline is parallel to the π₯-axis.
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And the midline is affected by vertical translations.
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When our curve is written in this format, π¦ equals π΄ times cos of π΅ times π₯ minus πΆ plus π·.
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π΄ is the amplitude, π΅ is the frequency, πΆ is the horizontal shift, and π· is the vertical shift.
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Our function π¦ equals five over four times cos times π over seven π₯ minus five plus 12 has a vertical shift of positive 12.
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Which means it has a midline at the line π¦ equals 12.
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If this is the line π¦ equals 12.
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And this cosine function is going to oscillate above and below this midline.