How do you find the period of #y=cos(2x)#?

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Answer 1 · 2018-04-11T21:34:41

#"Period" = pi#

If we express the cosine function in the following way:

#y=acos(bx+c)+d#

Then:

# \ \ \bb|a| \ \ \ ="the amplitude"#

#bb((2pi)/|b|) \ \="the period"#

#bb((-c)/b)= "the phase shift"#

# \ \ \ \bbd \ \ \="the vertical shift"#

For given function we have:

#|b|=2#

So period is:

#(2pi)/2=pi#

The graph confirms this:

enter image source here