kdo={Petr,Jana,Karel,Zbynek};
Map[ostrihejDoHola,kdo];
ostrihejDoHola/@kdo;

Apply[seznamJe,kdo]
seznamJe@@kdo

cisla=Range[100];
naDruhou[x_]:=(x^2);
naDruhou/@cisla;
Plus@@%

Plus@@(((#)^2)&/@Range[100])

test[1]

test[x_]:=x>2;
Select[{1,2,4,7,6,2},test]
Select[{1,2,4,7,6,2},#>2&]

h:=((#1)^2)+((#2)^4)&;
h[Pi,E]

Sin'
Sin'[x]

Sin'

D[Sin[0.1],0.1]

Plot[Sin'[x],{x,0,6}]
Plot[D[Sin[x],x],{x,0,6}]

(Log[x]*Sin[x]*x+x)'

vyr=Log[x]*Sin[x]*x+x
D[vyr,x]
fce[x_]:=Log[x]*Sin[x]*x+x;
fce'[x]

rce={u==R*i[t]+L*i'[t]+uc[t],i[t]==c*uc'[t]};
rce/.{jmeno_'[t]:>I*ω*jmeno,a_Symbol[t]:>a}

Table[(i^E),{i,5}]
%/.((a_)^(b_)):>(b^a)

Range[10]/.x_?(#>5&):>x-3
Range[10]/.x_?(True&):>x-3
Range[10]/.x_:>x-3

f[x_?(#<2&)]:=x
f[x_?(#≥2&)]:=(((x))^2)-2;
Plot[f[x],{x,0,4}]

?__

?___

f[x_Integer, y___] := Plus[y]^x;
f[1]
f[2,2]
f[2,2,2]

ClearAll[f,x]
f[n_]:=Re[Times@@(x/.Solve[0.==Plus@@(((x^(#))/(#!))&/@(Range[n+1]-1))])];
ListPlot[ukazka=f/@Range[20],PlotRange->All]

resx=Solve[x==a,x]
x/.resx[[1]]

res

Plus@@(x/.Solve[(x^3)+(Sqrt[t])*(x^2)+(t^2)*x+5==0,x])//Re;
Plot[%,{t,1,3},PlotStyle->Thick,AxesLabel->{"t","Re[x1+x2+x3]"}]

rce=(x^3)+(Sqrt[t])*(x^2)+(t^2)*x+5==0;
res=Solve[rce,x];
x1=x/.res[[1]];
x2=x/.res[[2]];
x3=x/.res[[3]];
Plot[Re[x1+x2+x3],{t,1,3},PlotStyle->Thick,AxesLabel->{"t","Re[x1+x2+x3]"}]