Fri Mar 13 20:23:01 2020 

newton_test
  R version 3.4.4 (2018-03-15) 
  newton seeks the root of an equation using the newton method.

  newton(x^2-1, 2*x, x, 1.0-3) =  1 

newton_test
  Normal end of execution.
Fri Mar 13 20:23:01 2020