Cos wave

 Here is an example of a cos wave 

consider x as theta (pi)

y = cos x , function for cos wave

plot data for x = [0, 45, 90, 180, 270, 360]

for  x =0 , y  = cos 0 = 1

x =45 , y =cos 45 = 0.707

x= 90 , y = cos 90 = 0

x = 180 , y  = cos 180  = -1

x = 270 , y = cos 270 = 0 

x = 360  , y= cos 360 = 1

so what is the use of this wave , when datas take the cos wave pattern

can be used to predict output for the inputs.

To understand more use calculator with scientific mode and check for the 

input x on the graph and the corresponding y graph value which is a cos function

it should  match .

Pattern are useful in machine learning problems ,for more check out the machine learning posts.