Quiet[Remove["Global`*"]];
$HistoryLength=2;
SetDirectory[NotebookDirectory[]];

NotebookDirectory[]

FileNames[]

data=Import["koeficientyReal.xls"][[1]];
MatrixForm[data];
data1=Drop[data,1];
Dimensions[data1];
soustava=Transpose[Drop[Transpose[data1],-1]];
praveStrany=Flatten[Transpose[Take[Transpose[data1],-1]]];

matSoust2=data[[2;;,;;-2]];
pravaStrana2=data[[2;;,-1]];

x=(A^(-1))b

{a,b,c,d,e,f}[[3;;5]]

reseni=Inverse[matSoust2].pravaStrana2

matSoust2.reseni-pravaStrana2//Chop

reseni2=LinearSolve[matSoust2,pravaStrana2];

reseni-reseni2

{{a,b},{c,d}} .{x, y}

{{a,b},{c,d}} * {x, y}

dataKompl=Import["koeficientyKomplex.xls"][[1]];

dataKompl2=Drop[dataKompl,2];
Dimensions[dataKompl2]

dataKompl3=Partition[#,2]&/@dataKompl2;

Range[10]

Range[1,100,5]

f[x_]:=x^2

#^2&/@{2,3,54,6}

f/@{2,3,54,6}

f@@{2,3,54,6}

Partition[Range[10],2]

dataKompl4=dataKompl3/.{a_,b_}:>a+I*b

dataKompl4//Dimensions

{1,2,4}//Total

{1,236,8a,gh,e}/. a->"asdasd"

{1,25,6,8}/. {25->v,1->f}

Drop[Transpose[dataKompl4],-1];

matKompl=Transpose[Drop[Transpose[dataKompl4],-1]]

pravaStranaKompl=Take[Transpose[dataKompl4],-1][[1]];

resKompl=LinearSolve[matKompl,pravaStranaKompl];

matKompl.resKompl-pravaStranaKompl//Chop

eqn=x==1+Tanh[0.5x]
sol=FindRoot[eqn,{x,0}]
(eqn/.lhs_==rhs_:>((lhs-rhs)/(0.5*(rhs+lhs))))/.sol

FindRoot[Sin[x]==0,{x,0}]

FindRoot[Sin[x]==0,{x,100}]

Integrate[Sin[x]/x,{x,1,2}]

NIntegrate[Sin[x]/x,{x,1,2}]

vyr1=Integrate[Sin[x]/x,{x,1,t}]
dervyr1=D[vyr1,t]
Plot[dervyr1,{t,1,2}]

dataProloz={{1,2},{-3,5},{0,1},{4,-3}}

modelProl=a*x^3+b*x^2+c*x+d

koefProl=FindFit[dataProloz,modelProl,{a,b,c,d},x]

modelProl/.koefProl

dataProloz={{1,2},{-3,5},{0,1},{4,-3}}
proklad=Fit[dataProloz,{1,x,(x^2),(x^3)},x]
Show[ListPlot[dataProloz,PlotStyle->{Red, PointSize[0.02]},AxesLabel->{"x","f[x]"}],Plot[proklad,{x,-3,4}]]

I^I//ComplexExpand