Question 588281
Amplitude:


In general, the amplitude of {{{y = Acos(Bx-C)+D}}} is {{{abs(A)}}}


In your case, {{{A=4}}}. So {{{abs(A)=abs(4)=4}}}. So the amplitude of {{{y=4cos(3.14x)+4}}} is <font color="red">4</font>.


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Going back to the general equation {{{y = Acos(Bx-C)+D}}}, the period is {{{T=(2pi)/B}}}


In the equation {{{y=4cos(3.14x)+4}}}, the value of B is {{{B=3.14}}}. So the period is {{{T=(2pi)/B = (2pi)/(3.14) = 2.00101442903809}}}


So the period is approximately <font color="red">2.00101442903809</font>


Note: this value is close to 2 because 3.14 is close to {{{pi}}}. If you really meant {{{pi}}} instead of {{{3.14}}}, then the period would truly be 2.


A graph of {{{y=4cos(3.14x)+4}}} is shown below


{{{ drawing(500, 500, -5, 5, -10, 10,
 graph( 500, 500, -5, 5, -10, 10,4cos(3.14x)+4)

)}}}