Write a cosine function for the sinusoid.

Step 1: Find the maximum and minimum values.
1 and -3

Step 2: Identify one cycle of the cosine function on the graph to form the model function.
y=2cos(x-x2)-1

Step 3: Find the amplitude and period. Show your formula and work for credit.
1-(-3)2=42=2 amplitude is 2
Step 4: Use the period to determine b. Show your formula and work for credit.
T=2b, B=22, b=

Step 5: Identify the vertical shift, d. Show your formula and work for credit.
d=1-32, d=-22, d=-1

Step 6: Use the graph to identify the phase shift.
C = ½(right)

Step 7: Use phase shift and b to determine c. (phase shift = -c/b) Show your formula and work for credit.

3 answers

c = -1/(2)(2) = -1/4

what's the function

The cosine function for the given sinusoid is:

y = 2cos(2x + π/4) - 1