View Single Post
Old 04-10-2005, 02:31 PM   #6 (permalink)
phukraut
Addict
 
I don't have the answer, but to provide some data, here is the expansion of the derivatives of exp(sin(0)) for n=0,1,2,...,15:

1, 1, 1, 0, -3, -8, -3, 56, 217, 64, -2951, -12672, 5973, 309376, 1237173, -2917888.

The OEIS gives <a href="http://www.research.att.com/projects/OEIS?Anum=A002017">A002017</a>, which doesn't provide a general formula unfortunately.

If, in f<sub>n</sub>(t), we let s=sin(t) and c=cos(t), then the expansion looks like this:

f<sub>0</sub>(t) = 1s<sup>0</sup>c<sup>0</sup>.

f<sub>1</sub>(t) = 1s<sup>0</sup>c<sup>1</sup>.

f<sub>2</sub>(t) = -1s<sup>1</sup>c<sup>0</sup> + 1s<sup>0</sup>c<sup>2</sup>.

f<sub>3</sub>(t) = -1s<sup>0</sup>c<sup>1</sup> - 3s<sup>1</sup>c<sup>1</sup> + 1s<sup>0</sup>c<sup>3</sup>.

And so on. The coefficients here are trinomials. If I get any further I'll post here.

Last edited by phukraut; 04-10-2005 at 02:44 PM..
phukraut is offline  
 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76