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3 years ago

PLEASE HELP Find the length of BC

Mathematics

1 answer:

Law Incorporation [45]3 years ago

4 0

Answer:

BC or n=72

Step-by-step explanation:

ABC≈DEF

$\frac{AB}{DE} =\frac{BC}{EF}=\frac{AC}{DF}=k$

$\frac{54}{9} =\frac{n}{12}$

$9n=54*12$

$9n=648$ (then divide both sides by 9.)

$n=72$

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Expand the numerator to apply the identity again:

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$\cos^6x=\dfrac{1+3\cos2x+3\left(\frac{1+\cos2(2x)}2\right)+\cos2x\left(\frac{1+\cos2(2x)}2\right)}8$

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$\cos^6x=\dfrac5{16}+\dfrac{15}{32}\cos2x+\dfrac3{16}\cos4x+\dfrac1{32}\cos6x$

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