Cos(x) is infinitely differentiable, can be expanded using Taylor's series.
The series about c can be expressed as
Substituting cos(x), c= π /4,we have
and since
we can simplify the expansion to
Note that the sign pattern is - - + + - - + + - - ..... following the sign pattern of the derivatives of cos(x).
The series about c can be expressed as
Substituting cos(x), c= π /4,we have
and since
we can simplify the expansion to
Note that the sign pattern is - - + + - - + + - - ..... following the sign pattern of the derivatives of cos(x).