Find the value of . Any method is fine. (obviously the fastest is best...)
Thanks!
I don't know if this is more or less work than earboth's method. (I guess it depends on how many Maclaurin series you know.)
So
(We only need the first term in the sine expansion since we are approximating this to third order in x. Noticing this saves a lot of time since we don't have to expand the cubic.)
-Dan