static double derivFunc ( double x ) {
  return 3 * x * x - 2 * x ;
}

static double derivFunc ( double x ) { return 3 * x * x - 2 * x ; }
(method_declaration (modifiers) type: (floating_point_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (floating_point_type) name: (identifier))) body: (block (return_statement (binary_expression left: (binary_expression left: (binary_expression left: (decimal_integer_literal) right: (identifier)) right: (identifier)) right: (binary_expression left: (decimal_integer_literal) right: (identifier))))))