The formula for a Maclaurin series expansion is
The derivatives of the function sin x and their values at x = 0 are given by
f(x) = sin x f(0) = 0
f '(x) = cos x f '(0) = 1
f ''(x) = - sin x f ''(0) = 0
f '''(x) = - cos x f '''(0) = -1
f ''''(x) = sin x f ''''(0) = 0
f '''''(x) = cos x f '''''(0) = 1
..................... ...............
Substituting the values of f(0), f '(0), f ''(0), ... into 1) we have
or