Answer:
y = cos(x)
Step-by-step explanation:
This graph of the cosine function has no shifting or scaling. It is a plain cosine function:
y = cos(x)
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Additional comment
It will be worth your time to learn to recognize the sine and cosine functions. They have a maximum of +1, a minimum of -1 and a period (horizontal distance between corresponding points) of 2π. The sine function is symmetrical about the origin. The cosine function is symmetrical about the y-axis. The maximum slope (near the zero-crossings) is 1.
