text: from ROOT import  * 
  import sys
  
  def main(argv=sys.argv):  
  
  
      pi=3.14159265359
      c=TCanvas("c1", "c1", 800,600)
   
  
      fun1=TF1("f2", "1.2732*(1-0.6366*x)", 0, pi/2) 
      fun1.SetLineColor(kBlue)             
      fun1.SetFillColor(1)                  
      fun1.SetTitle("")                     
      fun1.GetXaxis().SetTitle('x')         
      fun1.GetYaxis().SetTitle('y')         
                                       
      fun1.Draw()
  
  
  
      fun=TF1("f1", "0.9*cos(x)", 0, pi/2) 
      fun.SetLineColor(kBlack)             
      fun.SetFillColor(1)                  
      fun.SetTitle("")                     
      fun.GetXaxis().SetTitle('x')         
      fun.GetYaxis().SetTitle('y')         
      fun.Draw("SAME")  
  
  
  
  
      fun2=TF1("f3", "0.785*cos(x)/(1-2*x/3.1415)", 0, pi/2)
      fun2.SetLineColor(kRed)                        
      fun2.SetFillColor(1)                            
      fun2.SetTitle("")                               
      fun2.GetXaxis().SetTitle('x')                   
      fun2.GetYaxis().SetTitle('y')                   
  
      fun2.Draw("SAME")
  
      leg=TLegend(0.7, 0.6, 0.9, 0.8)
      leg.AddEntry(fun1, "g(x)", "L")
      leg.AddEntry(fun2, "w(x)", "L")
      leg.AddEntry(fun, "p(x)", "L")
  
  
      leg.Draw()
      c1.SaveAs("result.png")
          
  
  
  if __name__ == "__main__":    
      sys.exit(main())      
  