Find the Maclaurin series for the function.
f(x) = cos 3x
Part 1 of 3
To find Maclaurin series for the function
f(x) = cos 3x,
recall the power series for the elementary function cos x.
cos x =
∞
(−1)nx2n2n!
n = 0
Part 2 of 3
To write the Maclaurin series for the function
f(x) = cos 3x,
replace x by
in the series for cos x.
cos 3x =
∞
(−1)n
2n
(2n)!
n = 0