Question 1142058
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If you are given the function


    y = A*cos(bx + c) + d


and when you are asked to determine the period of this function, then


    - the value of the amplitude  "A"  <U>does not matter for the answer</U>;

    - the value of the horizontal shift  "c"  <U>does not matter for the answer</U>;

    - the value of the vertical shift  "d"  <U>does not matter for the answer</U>.


The only value, which does matter to answer this question, is the coefficient  "b"  at variable x.


The formula to find the period  "T"  then is


    b*T = {{{2pi}}},     (1)


which gives you the answer


    the period T is equal  T = {{{2pi/b}}}.


It is because  {{{2pi}}}  is the period of the function  cos(x).


In your case, the period  T = {{{2pi/4}}} = {{{pi/2}}}.
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