How do you find the amplitude, period and phase shift for y=cos3(theta-pi)-4?

1 Answer
Mar 30, 2018

See below:

Explanation:

Sine and Cosine functions have the general form of

f(x)=aCosb(x-c)+d

Where a gives the amplitude, b is involved with the period, c gives the horizontal translation (which I assume is phase shift) and d gives the vertical translation of the function.

In this case, the amplitude of the function is still 1 as we have no number before cos.

The period is not directly given by b , rather it is given by the equation:
Period=((2pi)/b)
Note- in the case of tan functions you use pi instead of 2pi.

b=3 in this case, so the period is (2pi)/3

and c=3 times pi so your phase shift is 3pi units shifted to the left.

Also as d=-4 this is the principal axis of the function, i.e the function revolves around y=-4