f1 <- function ( x )

#*****************************************************************************80
#
## f1() evaluates a nonlinear system of 1 equation.
#
#  Licensing:
#
#    This code is distributed under the MIT license.
#
#  Modified:
#
#    08 April 2021
#
#  Author:
#
#    John Burkardt
#
#  Input:
#
#    double X[N], the variable values.
#
#  Output:
#
#    double FX[N], the function values.
#
{
  n <- length ( x )

  e <- 0.8
  m <- 5.0

  fx <- x - m - e * sin ( x )

  return ( fx )
}