Sine Waves

The main thing to understand here is the equation of the sine wave, and how each variable affects the wave (how it looks).

Sine waves are a cyclic function that oscillates. 

Their general formula is the following:

Where:

• $A$ is the amplitude (the height of the wave, IE the maximum / minimum value it reaches from its center)
  
• f is the frequency (the number of cycles within a period of 2π seconds)
  
• t is the time (this is usually the input variable)
  
• ϕ is the phase (the offset left or right of the wave)
  

Link to a desmos page where you can play with these variables till you have an intuitive understanding of how they effect the graph

Note that there are also other forms of expressing the above equation that may be used, but for the purposes of signal analysis, the above form is probably the easiest to work with!