Question 420692
write an equation of the cos function with an amplitude of 4, period of 6, phase shift -pi, and verticle shift of -5.

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Basic equation of cos function: y=ACos(Bx-C)
A=amplitude
B=coefficient of x
Period=2pi/B
Phase shift=C/B
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Given amplitude=4=A
Given Period = 6=2pi/B
B=2pi/6=pi/3
Given phase shift=-pi=C/B
C=B*-pi=(pi/3)*-pi=-pi^2/3
Given vertical shift=-5 (Curve is bumped down 5 units)
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Equation:
y=4Cos(pi/3x+pi^2/3)-5