Can anyone do this integral
x*tanx dx
this looks easy but it isn't....
gve me the final answer and then differnetiate it to see whether u get x*tanx
2006-10-31 04:29:17 · 2 answers · asked by nice dude 1 in Science & Mathematics ➔ Mathematics
Unfortunately, this is a well-known non-elementary
integral. First try to integrate it by parts.
It will boil down to integrating log(cos x).
This is where the road ends. The integral
of log(cos x) involves the dilogarithm function.
To try this last part, let u = cos x, x = arccos u,
dx = -1/sqrt(1-x^2) and see what happens!
2006-10-31 07:10:46 · answer #1 · answered by steiner1745 7 · 0⤊ 0⤋
Errrmmmm....... Yeah. This one *is* a high-order b|tch, to say the least.
If you're an undergrad student taking a standard, lower-division 'Calclueless' class, there's no way in *hell* that this can be anything but a typo in your book.
If you're a grad student, good luck because this one is gonna get you into complex exponentials and transfinite polylog functions *real* quick âº
Doug
2006-10-31 12:46:55 · answer #2 · answered by doug_donaghue 7 · 0⤊ 0⤋