cosh

# File lib/cmath.rb, line 239
  def cosh(z)
    begin
      if z.real?
        cosh!(z)
      else
        Complex(cosh!(z.real) * cos!(z.imag),
                sinh!(z.real) * sin!(z.imag))
      end
    rescue NoMethodError
      handle_no_method_error
    end
  end