65X. Ejercicios - JulTob/Mathematics GitHub Wiki
Sea la sucesión (𝑎ₙ) definida por y 𝑎ₙ₊₁ = 6 − (8:𝑎ₙ)
a) Es constante para valores comprendidos entre (-∞,1]
b) Si 𝑎₁ = 3 la sucesión está acotada superiormente
c) Ninguna de las otras dos
Se puede estudiar el comportamiento ejecutando este trozo de código:
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;
with Ada.Float_Text_IO; use Ada.Float_Text_IO;
procedure test is
X: Float := 0.0;
begin
for n in -100..10 loop
x := 6.0-8.0/float(n);
Put(n);
Put(x);
new_line;
end loop;
end test;
-100 6.08000E+00
-99 6.08081E+00
-98 6.08163E+00
-97 6.08247E+00
-96 6.08333E+00
-95 6.08421E+00
-94 6.08511E+00
-93 6.08602E+00
-92 6.08696E+00
-91 6.08791E+00
-90 6.08889E+00
-89 6.08989E+00
-88 6.09091E+00
-87 6.09195E+00
-86 6.09302E+00
-85 6.09412E+00
-84 6.09524E+00
-83 6.09639E+00
-82 6.09756E+00
-81 6.09877E+00
-80 6.10000E+00
-79 6.10127E+00
-78 6.10256E+00
-77 6.10390E+00
-76 6.10526E+00
-75 6.10667E+00
-74 6.10811E+00
-73 6.10959E+00
-72 6.11111E+00
-71 6.11268E+00
-70 6.11429E+00
-69 6.11594E+00
-68 6.11765E+00
-67 6.11940E+00
-66 6.12121E+00
-65 6.12308E+00
-64 6.12500E+00
-63 6.12698E+00
-62 6.12903E+00
-61 6.13115E+00
-60 6.13333E+00
-59 6.13559E+00
-58 6.13793E+00
-57 6.14035E+00
-56 6.14286E+00
-55 6.14545E+00
-54 6.14815E+00
-53 6.15094E+00
-52 6.15385E+00
-51 6.15686E+00
-50 6.16000E+00
-49 6.16327E+00
-48 6.16667E+00
-47 6.17021E+00
-46 6.17391E+00
-45 6.17778E+00
-44 6.18182E+00
-43 6.18605E+00
-42 6.19048E+00
-41 6.19512E+00
-40 6.20000E+00
-39 6.20513E+00
-38 6.21053E+00
-37 6.21622E+00
-36 6.22222E+00
-35 6.22857E+00
-34 6.23529E+00
-33 6.24242E+00
-32 6.25000E+00
-31 6.25806E+00
-30 6.26667E+00
-29 6.27586E+00
-28 6.28571E+00
-27 6.29630E+00
-26 6.30769E+00
-25 6.32000E+00
-24 6.33333E+00
-23 6.34783E+00
-22 6.36364E+00
-21 6.38095E+00
-20 6.40000E+00
-19 6.42105E+00
-18 6.44444E+00
-17 6.47059E+00
-16 6.50000E+00
-15 6.53333E+00
-14 6.57143E+00
-13 6.61538E+00
-12 6.66667E+00
-11 6.72727E+00
-10 6.80000E+00
-9 6.88889E+00
-8 7.00000E+00
-7 7.14286E+00
-6 7.33333E+00
-5 7.60000E+00
-4 8.00000E+00
-3 8.66667E+00
-2 1.00000E+01
-1 1.40000E+01
0-Inf********
1-2.00000E+00
2 2.00000E+00
3 3.33333E+00
4 4.00000E+00
5 4.40000E+00
6 4.66667E+00
7 4.85714E+00
8 5.00000E+00
9 5.11111E+00
10 5.20000E+00
Vemos que el comportamiento de la serie entre -100 y 1 no es constant para todo el intervalo.
Por ejemplo, para 𝑎₁ = -4, 𝑎₂ = 8, y 𝑎₃ = 5
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;
with Ada.Float_Text_IO; use Ada.Float_Text_IO;
procedure test is
X: Float := 3.0;
begin
for n in 1..100 loop
x := 6.0-8.0/x;
Put(n);
Put(x);
new_line;
end loop;
end test;
1 3.33333E+00
2 3.60000E+00
3 3.77778E+00
4 3.88235E+00
5 3.93939E+00
6 3.96923E+00
7 3.98450E+00
8 3.99222E+00
9 3.99610E+00
10 3.99805E+00
11 3.99902E+00
12 3.99951E+00
13 3.99976E+00
14 3.99988E+00
15 3.99994E+00
16 3.99997E+00
17 3.99998E+00
18 3.99999E+00
19 4.00000E+00
20 4.00000E+00
Vemos que el comportamiento de la sucesión tiende a 4 con 𝑎₁=3. Por tanto está acotada superiormente.
b) ✔
$\lim_{n\rightarrow ∞}\frac{\sum_{k=1} k^n }{n^p}$
Dada la sucesión $a_n = (1+n̈)+(-1)ⁿ(1-3n̈)$
$a_n = (1+n̈)+(-1)ⁿ(1-3n̈)$
Pares/Impares
$a_p = (1+p̈)+(1-3p̈)$
$a_m = (1+m̈)-(1-3m̈)$$a_p∞ = (1)+(1) = 2$
$a_m∞ = (1)-(1)= 0$
$\lim_{n\rightarrow ∞}\frac{n! }{n^n}$
$\frac{n! }{n^n}$
$\frac{n·(n-1)...3·2·1 }{n·n·n·n·n...n}$
$\frac{n}{n} ·...· \frac{3}{n} \frac{2}{n} \frac{1}{n}$
$a_i = i/n$
$a_i ≤ 1$
$∏a_i ⟶ 0$