//Chapter-2,Example2_4_3,pg 2-25

//as 3rd order line of wavelength lam is coincide with 4th order wavelength 4992 A.

m_1=3                                                    //3rd order 

m_2=4                                                    //for 4th order

wavelength_2=4992                                        //for 4th order

wavelength_1=m_2*wavelength_2/m_1 

printf('\nwavelength of light is  = %.0f A.',wavelength_1)