numeric approximation



On Tue, 7 Feb 2012 09:17:06 +0100
Olive <not0read0765 at yopmail.com> wrote:

> My experiment:
> 
> (%i1) f(t):=''(integrate(1/(sin(x)^2+log(x)),x,1,t));
>                                  t
>                                 /
>                                 [         1
> (%o1)                   f(t) := I  ---------------- dx
>                                 ]     2
>                                 /  sin (x) + log(x)
>                                  1
> (%i2) f(5), numer;
>                              5
>                             /
>                             [         1
> (%o2)                       I  ---------------- dx
>                             ]     2
>                             /  sin (x) + log(x)
>                              1
> It seems that (%i1) correctly define a function f(t) and maxima is
> indeed able to derive it. Why (%o2) does not give a numeric
> approximation of f(5)? What I have to do to get it? How can I plot f?

By reading the documentation, I can define:

f_numer(t):=quad_qag(1/(sin(x)^2+log(x)),x,1,t,1)[1];

and f_numer give a numeric approximation of f. But is it possible to
connect f(t) and f_numer(t)? Both represent intrinsically the same
function (f(t) is the symbolic representation of f_numer(t)).

Olive