How do you graph y=12+2sin(3xπ2)?

1 Answer
Oct 4, 2016

The amplitude is 2, the period is 2π3, the phase shift is π6 right, and the vertical shift is 12.

Explanation:

First, rewrite the problem as y=2sin(3xπ2)+12

This is of the form y=Asin(BxC)+D where

A= the amplitude

2πB= the period

CB= the phase shift

D= the vertical shift

In this example, the amplitude A=2. Amplitude is the vertical distance from the "midline" to the max or min. It is not the the distance from max to min.

Period =2πB=2π3. One complete cycle of the sin graph will be 2π3 horizontal units wide.

Phase shift =CB=π23=π6 The graph will be shifted π6 units to the right.

Vertical shift D=12 units up.

Let's look at each transformation of the graph. First y=sinx

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Next, change the amplitude to 2
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Now change the period from 2π to 2π3

enter image source here

Next, add a phase shift of π6 to the right. The red graph has the phase shift. The blue is without the phase shift.
enter image source here

Lastly, add a vertical shift of 12 units up.
enter image source here