What Are Frequency of Beats and Effective Frequency in Wave Interference?

[InvalidID]

So my textbook says that the equation for the frequency of beats is $|{ f }_{ 1 }-{ f }_{ 2 }|$ and the equation for effective frequncy is $\frac { { f }_{ 1 }+{ f }_{ 2 } }{ 2 }$, but what is frequncy of beats and effective frequency anyways?

Edit: Opps. Should've posted it here: https://www.physicsforums.com/forumdisplay.php?f=61

 

[ehild]

See:
http://hyperphysics.phy-astr.gsu.edu/%E2%80%8Chbase/audio/sumdif.html#c1

ehild

 

[InvalidID]

See:
http://hyperphysics.phy-astr.gsu.edu/%E2%80%8Chbase/audio/sumdif.html#c1

ehild

Thanks for the that! But what is effective frequency? The superimposed wave looks weird like this: http://hyperphysics.phy-astr.gsu.edu/%E2%80%8Chbase/sound/imgsou/beat4.gif

So is the effective frequency the frequency of the wave in the dotted line or the solid line?

 

[ehild]

The solid line.

ehild