Árpád apánk

Blog. ennyi. semmi több. megtalalsz itt jó pár infót rólam, az életemről, meg néhány érdekes dolgot is, csak épp fejlesszem ki. addig is türelem kispajtás :)

2008/05/20

otodik

> f:=x->sqrt(x);

f := sqrt

> ap:=x->x/4+1;

ap := proc (x) options operator, arrow; 1/4*x+1 end proc

> plot([f(x),ap(x)],x=1..6,color=[red,blue]);

[Plot]

> [evalf(4+i/10),evalf(f(4+i/10)),evalf(ap(4+i/10)),evalf(f(4+i/10)-ap(4+i/10))] $i=-5..5;

[3.500000000, 1.870828693, 1.875000000, -0.41713070e-2], [3.600000000, 1.897366596, 1.900000000, -0.26334040e-2], [3.700000000, 1.923538406, 1.925000000, -0.146159400e-2], [3.800000000, 1.949358869, 1...[3.500000000, 1.870828693, 1.875000000, -0.41713070e-2], [3.600000000, 1.897366596, 1.900000000, -0.26334040e-2], [3.700000000, 1.923538406, 1.925000000, -0.146159400e-2], [3.800000000, 1.949358869, 1...[3.500000000, 1.870828693, 1.875000000, -0.41713070e-2], [3.600000000, 1.897366596, 1.900000000, -0.26334040e-2], [3.700000000, 1.923538406, 1.925000000, -0.146159400e-2], [3.800000000, 1.949358869, 1...[3.500000000, 1.870828693, 1.875000000, -0.41713070e-2], [3.600000000, 1.897366596, 1.900000000, -0.26334040e-2], [3.700000000, 1.923538406, 1.925000000, -0.146159400e-2], [3.800000000, 1.949358869, 1...

>

f := sqrt

> linearis:=proc(f,a,x)
return (f(a)+D(f)(a)*(x-a));

end proc;

>

>

>

> f:=x->sqrt(x);

linearis := proc (f, a, x) return f(a)+D(f)(a)*(x-a) end proc

f := sqrt

> linearis(f,4,2);

3/2

> kvadratikus:=proc(f,a,x)
return (f(a)+D(f)(a)*(x-a)+1/2*(D@@2)(f)(a)*(x-a)^2);

end proc;

kvadratikus := proc (f, a, x) return f(a)+D(f)(a)*(x-a)+1/2*`@@`(D, 2)(f)(a)*(x-a)^2 end proc

> kvadratikus(f,4,2);

>

23/16

> taylor1:=proc(f,n,a,x)
local i, t;

t:=0;

for i from 0 to n do

t:=t+(D@@i)(f)(a)/i!*(x-a)^i;

end do;

return t;

end proc;

taylor1 := proc (f, n, a, x) local i, t; t := 0; for i from 0 to n do t := t+`@@`(D, i)(f)(a)*(x-a)^i/factorial(i) end do; return t end proc

> taylor1(f,5,0,x);

x-1/6*x^3+1/120*x^5

> f:=x->sin(x);

f := sin

>

> ts:=taylor(exp(x),x=3,5);

ts := series(exp(3)+exp(3)*(x-3)+1/2*exp(3)*(x-3)^2+1/6*exp(3)*(x-3)^3+1/24*exp(3)*(x-3)^4+O((x-3)^5),x = 3,5)

> pts:=convert(ts,'polynom');

pts := exp(3)+exp(3)*(x-3)+1/2*exp(3)*(x-3)^2+1/6*exp(3)*(x-3)^3+1/24*exp(3)*(x-3)^4

> fts:=x->exp(3)+exp(3)*(x-3)+1/2*exp(3)*(x-3)^2+1/6*exp(3)*(x-3)^3+1/24*exp(3)*(x-3)^4;

fts := proc (x) options operator, arrow; exp(3)+exp(3)*(x-3)+1/2*exp(3)*(x-3)^2+1/6*exp(3)*(x-3)^3+1/24*exp(3)*(x-3)^4 end proc

> evalf(fts(3.5));

33.10975227

> g:=x->1/sqrt(1-4*x);

g := proc (x) options operator, arrow; 1/sqrt(1-4*x) end proc

> a:=taylor(g(x),x=0,5);

a := series(1+2*x+6*x^2+20*x^3+70*x^4+O(x^5),x,5)

> fts:=unapply(a,x);

>

fts := proc (x) options operator, arrow; series(1+2*x+6*x^2+20*x^3+70*x^4+O(x^5),x,5) end proc

> with(combinat);

Warning, the protected name Chi has been redefined and unprotected

[Chi, bell, binomial, cartprod, character, choose, composition, conjpart, decodepart, encodepart, fibonacci, firstpart, graycode, inttovec, lastpart, multinomial, nextpart, numbcomb, numbcomp, numbpar...[Chi, bell, binomial, cartprod, character, choose, composition, conjpart, decodepart, encodepart, fibonacci, firstpart, graycode, inttovec, lastpart, multinomial, nextpart, numbcomb, numbcomp, numbpar...

> binomial(2*40,40);

107507208733336176461620

> coeftayl(g(x),x=0,40);

107507208733336176461620

>

> z:=x->1/(1-x)^(n+1);

z := proc (x) options operator, arrow; 1/(1-x)^(n+1) end proc

> b:=coeftayl(z(x),x=0,3);

b := (n+1)^3/6+(n+1)^2/2+n/3+1/3

> subs(n=5,b);

56

> binomial(8,3);

56

> explim:=Limit(Sum(x^i,i=0..n),n=infinity);

explim := Limit(Sum(x^i, i = 0 .. n), n = infinity)

> explim1:=limit(sum(x^i,i=0..n),n=infinity);

explim1 := limit(x^(n+1)/(x-1)-1/(x-1), n = infinity)

> subs(x=0.3,explim1);

>

limit(-1.428571429*.3^(n+1)+1.428571429, n = infinity)

> evalf(%,20);

1.4285714290000000000

> 1/(1-0.3);

1.428571429

>