PARI/gp

[Xorter]

Hi, again!
I need your help in PARI/gp. I would like to substitute a value into x of sin(x):

Code:

subst(sin(x),x,1)

But it returns with error. Why? Please, help me.

[Gottfried]

Hi, again!
I need your help in PARI/gp. I would like to substitute a value into x of sin(x):

Code:

subst(sin(x),x,1)

But it returns with error. Why? Please, help me.

Code:

subst(Pol(sin(x)),x,1)

should work. But why not simply do

Code:

sin(1)

?

[Xorter]

Hi, again!
I need your help in PARI/gp. I would like to substitute a value into x of sin(x):

Code:

subst(sin(x),x,1)

But it returns with error. Why? Please, help me.

Code:

subst(Pol(sin(x)),x,1)

should work. But why not simply do

Code:

sin(1)

?

Oh, it was simplier than I thought. Thank you, my friend!
Well, because I have found a new type of integration and derivation. These are iterated! And I needed substitution in a function in my gp. Really amazing. I am going to share my results on this forum as soon as possibly.
(May be the key to determine what between addition and multiplication is.)
Just wait a few days, please.

[Xorter]

But somewhy it does not work with gamma function.

[sheldonison]

But somewhy it does not work with gamma function.

sin(x+1) or gamma(x+1)

[Xorter]

But somewhy it does not work with gamma function.

sin(x+1) or gamma(x+1)

I have determined the graphs with sin functions, but now I would like to work with gamma, too.
These methods are the generalizations of the integration and derivation...

[Xorter]

Hi, again!

Here is another problem. I would like to calculate this productum but without success:

Code:

subst(exp(1/x),x,1/1000)

Why?

[Gottfried]

Hi, again!

Here is another problem. I would like to calculate this productum but without success:

Code:

subst(exp(1/x),x,1/1000)

Why?

The error message in my (old) Pari/GP-system is                          

exp(1/'x)
   *** exp: negative exponent in gexp.

I don't think they have anything new implemented for this problem so far.

[Xorter]

I got the following error message:

  ***   at top-level: subst(exp(1/x),x,1/1000)

  ***                       ^------------------
  *** exp: domain error in exp: valuation < 0

My question is that how can we solve this problem?

[Gottfried]

I got the following error message:

  ***   at top-level: subst(exp(1/x),x,1/1000)

  ***                       ^------------------
  *** exp: domain error in exp: valuation < 0

My question is that how can we solve this problem?

Perhaps it is meaningful for you to replace 1/x by exp(-u) where u=log(x) ? At least this gives a power series (more precisiely a puisieux-series)