TempExactFun = @(time)14.6*exp(-1.1*time);
timeMeasured = linspace(0,2,41);
TempMeasured = round(TempExactFun(timeMeasured));
CoefQuarticFit=polyfit(timeMeasured, TempMeasured,4);
timePlot=linspace(0,2,200);
derTempExactPlot=-1.1*TempExactFun(timePlot);
derCoefQuarticFit=polyder(CoefQuarticFit)
derTempQuarticFitPlot=polyval(derCoefQuarticFit,timePlot);
plot(timePlot,derTempExactPlot,'--k',...
    timePlot,derTempQuarticFitPlot,'g')
