EZ Graph - Cosine Function, Amplitude Variable

Click the 'Draw graph' button in the lower left corner of the EZ Graph app. Explanation below.

Here is the conventional notation for these cosine functions and the computer language type of notation used with EZ Graph:

 

f1(x) = A cos(x) translates to EZ Graph as f1(x) = A * cos(x)
f2(x) = cos(x) translates to EZ Graph as f2(x) = cos(x)

 

Notice the necessary multiplication operator (*) in the EZ Graph notation between A and cos(x)for f1(x).