How do you graph y=2cos5xy=2cos5x?

1 Answer
Oct 28, 2016

Graph a cosine function with an amplitude of 22 and a period of (2pi)/52π5.

Explanation:

Graph y=2cos5xy=2cos5x.

This equation is in the form y=AcosBxy=AcosBx where

A=A=amplitude and (2pi)/B=2πB= the period.

Amplitude is the distance on the y-axis between the center line of the graph and the "peak" or "trough".

Period is the distance on the x-axis of one full "cycle" or "repeat" of the graph.

Let's start with y=cosxy=cosx.. It has an amplitude of 11 and a period of 2pi2π.

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Next, let's graph y=2cosxy=2cosx. Notice the amplitude has doubled from 11 on the red graph to 22 on the blue graph.

demos

Last, let's look at y=2cos5xy=2cos5x in green. The period is (2pi)/52π5.
In other words, one complete "cycle" of cosine is graphed between zero and (2pi)/52π5.
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