Markiyan Hirnyk

Markiyan Hirnyk
8 years, 301 days

These are questions asked by Markiyan Hirnyk

How to calculate the integral of (z-z0)*z/sqrt((x-x0)^2+(y-y0)^2+(z-z0)^2)
over the unit sphere {(x,y,z):x^2+y^2+z^2<=1}
under the assumtion x0^2+y0^2+z0^2<=1 (x0^2+y0^2+z0^2>1)?
Its physical interpretation suggests the integral can be expressed through  elementary functions of the parameters.

My tries are
VectorCalculus:-int((z-z0)*z/sqrt((x-x0)^2+(y-y0)^2+(z-z0)^2),[x,y,z]=Sphere(<0,0,0>,1)) assuming x0^2+y0^2+z0^2<=1;


[r,psi,theta]=Parallelepiped(0..1,0..Pi,0..2*Pi)) assuming x0^2+y0^2+z0^2<=1;

The both are spinning on my comp. Also


is spinning.
Edt. The omitted part of the code assuming x0^2+y0^2+z0^2<=1 is added.

How to calculate floor(10^(10^(10^(10^(10^(-10^10))))))? My simpleminded try is

Error, numeric exception: underflow
PS. I think that is about 10^(10^10).

Let us consider the expression

f := log[x](1+(x^a-1)*(x^b-1)/(x-1));
Does it define a convex function on the interval 0..1 and on the interval 1..infinity if the parameters a>0, a< 1, b >0, b <1?

My try is



At the same time I have got problems in the general case. For example,

Error, (in @) too many levels of recursion


That's all right if



Is it possible to numerically calculate  the integral

int((-12*y^2+1)*ln(abs(Zeta(x+I*y)))/(4*y^2+1)^3, [y = 0 .. infinity, x = 1/2 .. infinity])

in Maple?

The code

int((-12*y^2+1)*ln(abs(Zeta(x+I*y)))/(4*y^2+1)^3, [y = 0 .. infinity, x = 1/2 .. infinity],numeric,epsilon=0.1)

has been executed on my comp  without any output since this morning.




We have two texts in a certain language, represented as Maple  strings,  e. g.
"die einkommen der landwirte sind fuer die abgeordneten ein
buch mit sieben siegeln um dem abzuhelfen muessen dringend alle
subventionsgesetze verbessert werden" and
"die steuern auf vermoegen und einkommen sollten nach meinung
der abgeordneten nachdruecklich erhoben werden dazu muessen die
kontrollbefugnisse der finanzbehoerden dringend verbessert werden".
We have to find the maximal common subsequence of the words in the both texts,
i.e. "die  einkommen der abgeordneten muessen dringend verbessert werden" for
the above. If there are a few such ones, then only one is enough. How to program
that by SringTools and/or EssayTools in maximum efficient way? A compiled procedure is welcome.

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