The parent cosine function has the following key features, starting from the origin.
The equation of the function is y = cos(x)
The function starts with a maximum value at x = 0, which is 1. It then reduces to zero and then to its minimum value which -1 and then back to zero.This cycle continues as shown in the figure below.
So the sequence of change for a cosine function is {Maximum, Zero, Minimum, Zero, Maximum}
The period of cosine function is 2π, which means the cosine function will start repeating its values after a change of 2π in x values.
