1+1
a=5

a

a+1

a+b

a=b;

a

6d=47

6d
6*d

6 d
7 8

%

%%%%%%%%%

%

?%

%13

?=

?==

sin[5]
Sin[5]
Sin[5.]

Sin[5]
N[Sin[5]]

Sin[5]//N

5//Sin
5//Sin//N
(5//Sin)//N

vysl=Solve[(x^3)+c*(x^2)+14==d,x];

Ukazka hranatych zavorek

vysl[[1]]
vysl[[1]]/.c->5
vysl[[1]]/.{c->5,d->6}//N
(x/.(vysl[[1]]/.{c->5,d->6}//N))+1
(*takto lze psat komentare*)

I

?Plot

Plot[Sin[franta],{franta,-2,2},PlotLabel->"Sin[franta]",AxesLabel->{"franta","Sin[franta]"},PlotStyle->RGBColor[1,0.5,0]]

Plot[Sin[franta],{franta,-2,2},PlotLabel->"Sin[franta]",AxesLabel->{"franta","Sin[franta]"},PlotStyle->{Thickness[0.05],RGBColor[1,0,0],Dashing[0.1]}]

Plot[{Sin[t],Cos[t]},{t,-3,3},PlotStyle->{{Hue[0.1],Dashing[0.3]},{Hue[0.5],Thickness[0.02]}},AxesLabel->{"osa x","osa y"}]

{0,1,2,3}

Table[i,{i,1,10}]
Table[2i,{i,1,10}]
Table[i*opice,{i,1,10}]
Table[Sin[i]//N,{i,1,10}]
Sin[{2,3}]
{Sin[1],Sin[2]}//N

listik={{alfa,romeo},{baba,dedek},{ka,{ba,{ra}}}};

listik[[1,2]]

listik[[-1,2,1]]

?/.

rce=(x^3)+(x^2)+(a^2)*x+(a^3)==0;
res=Solve[rce,x];
iks1=x/.res[[1]];
Plot[Abs[iks1],{a,-1,1},PlotStyle->Thick,AxesLabel->{"a","x1"}]

Solve[x==1][[1]]
x/.%

iks1/.a->5.

?_

?:=

ClearAll[f];
x=5;
f[x_]:=(x^2)
f[2]

?=

ClearAll[f];
x=5;
f[x_]=(x^2)
f[1]

ClearAll[f,x];
f[x_]=(x^2)
f[1]

a[x]:=(x^2);
a[1]

g[5]

ClearAll[g,x];
g[x_]=Integrate[(x^3)*Sin[x],x];
Plot[g[x],{x,-1,1},PlotStyle->Thick,AxesLabel->{"x","int"},PlotRange->All]

Off[General::"newpkg",General::"obspkg"]
<<Calculus`VectorAnalysis`;
Off[General::"spell1"];

a=5;

ClearAll[h];
h[x_,y_]:=(x^2)+2x*y+3(y^2)+5+7x*y+8x-9y;
Plot3D[h[x,y],{x,-1,1},{y,-1,1},AxesLabel->{"x","y","int"}];
Print["derivace podle x= ",dx=D[h[x,y],x]]
Print["derivace podle y= ",dy=D[h[x,y],y]]
Print["druha derivace podle x= ",D[h[x,y],{x,2}]]
Print["druha derivace podle y= ",D[h[x,y],{y,2}]]
Print["Minimum je v bode  ",Solve[{dx==0,dy==0}][[1]]]

u=1;
R=100;
L=0.1;
c=(10^(-6));
rce1=u==R*i[t]+L*i'[t]+uc[t];
rce2=i[t]==c*uc'[t];
poc1=i[0]==0;
poc2=uc[0]==0;
res=DSolve[{rce1,rce2,poc1,poc2},{i[t],uc[t]},t]//Chop;
proud=i[t]/.res[[1]];
Plot[proud,{t,0,.01},PlotStyle->Thick,AxesLabel->{"t","i[A]"},PlotRange->All]

Manipulate[u=230*Sin[314t+fi];
R=100;
L=0.1;
c=(10^(-6));
rce1=u==R*i[t]+L*i'[t]+uc[t];
rce2=i[t]==c*uc'[t];
poc1=i[0]==0;
poc2=uc[0]==0;
res=NDSolve[{rce1,rce2,poc1,poc2},{i[t],uc[t]},{t,0,0.08}]//Chop;
proud=i[t]/.res[[1]];
Plot[proud,{t,0,.08},PlotStyle->Thick,AxesLabel->{"t","i[A]"},PlotRange->{Automatic,{-0.7,0.7}}],{fi,-Pi/2,Pi/2}]