Answer:
[tex]y=2\cos(2x+\frac{1}{4})-2[/tex]
or
[tex]y=-2\cos(2x+\frac{1}{4})-2[/tex]
Step-by-step explanation:
[tex]y=a cos(c(x-b))+d[/tex] has:
1) amplitude=|a|
2) phase shift=b
3) period=2pi/c
d) vertical shift=d
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You are given the amplitude is 2. This means a could either be 2 or -2.
You are given phase shift is -1/8. This means b is -1/8.
You are given the period is pi. So we need to solve pi=2pi/c.
pi=2pi/c
Dividing both sides by pi gives:
1=2/c
Multiply both sides by c gives:
c=2
The vertical shift is -2 so d=-2.
The equation could either be:
y=2cos(2(x-(-1/8)))-2
or
y=-2cos(2(x-(-1/8)))-2
Simplifying a little gives:
y=2cos(2x+1/4)-2
y=-2cos(2x+1/4)-2