2.9 Some special functions

# 
#                                           WORKSHEET#20
# 
# 
#                                         Some special functions
# 
# 
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> ?GAMMA
# 
# 
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> GAMMA(s):=int(exp(-t)*t^(s-1),t=0..infinity);

                                infinity
                                   /
                                  |                (s - 1)
                   GAMMA(s) :=    |      exp(- t) t        dt
                                  |
                                 /
                                 0
> GAMMA(0);
Error, (in GAMMA) singularity encountered

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> for n from 1 to 10 do GAMMA(n) od;

                                        1

                                        1

                                        2

                                        6

                                       24

                                       120

                                       720

                                      5040

                                      40320

                                     362880
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> n:='n':
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> for n from 1 to 10 do A[n]:=GAMMA(n+1)/GAMMA(n) od; 

                                    A[1] := 1

                                    A[2] := 2

                                    A[3] := 3

                                    A[4] := 4

                                    A[5] := 5

                                    A[6] := 6

                                    A[7] := 7

                                    A[8] := 8

                                    A[9] := 9

                                   A[10] := 10
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> GAMMA(1/2);

                                        1/2
                                      Pi
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> n:='n': A[n]:='A[n]': for n from 1 to 10 do \
A[n]:=GAMMA(n+(1/2))/GAMMA(n-(1/2)) od;

                                   A[1] := 1/2

                                   A[2] := 3/2

                                   A[3] := 5/2

                                   A[4] := 7/2

                                   A[5] := 9/2

                                  A[6] := 11/2

                                  A[7] := 13/2

                                  A[8] := 15/2

                                  A[9] := 17/2

                                  A[10] := 19/2
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> simplify(GAMMA(s+1)/GAMMA(s)-s);\


                                        0
> n:='n': A[n]:='A[n]':
> ?Si;
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> Si(x):=Int((sin(t))/t,t=0..x);

                                        x
                                        /
                                       |  sin(t)
                             Si(x) :=  |  ------ dt
                                       |     t
                                      /
                                      0
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> Si(0);

                                        0
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> Si(infinity);

                                     1/2 Pi
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> plot(sin(t)/t,t=0..100);
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# 

   ** Maple V Graphics **

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>  for k from 1 to 10 do X[k]:= evalf(Int(sin(t)/t,t=(k-1)*Pi..k*Pi)) od;\


                               X[1] := 1.851937052

                              X[2] := -.4337854758

                               X[3] := .2566102228

                              X[4] := -.1826005734

                               X[5] := .1418036205

                              X[6] := -.1159308846

                              X[7] := .09805155598

                              X[8] := -.08495423246

                              X[9] := .07494560683

                             X[10] := -.06704781224
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> sum('X[k]','k=1..10');

                                   1.539029081
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> evalf(Pi/2);

                                   1.570796327
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