In an optical calibration experiment, a diffraction grating is illuminated normally with two superimposed laser beams. One beam has a wavelength of 440 nm440\text{ nm}440 nm, and the other has an unknown wavelength of λ\lambdaλ.
It is observed that the fifth-order diffraction maximum for the 440 nm440\text{ nm}440 nm beam occurs at the same angle of diffraction as the fourth-order diffraction maximum for the beam of wavelength λ\lambdaλ.
What is the value of λ\lambdaλ?
352 nm352\text{ nm}352 nm
440 nm440\text{ nm}440 nm
550 nm550\text{ nm}550 nm
880 nm880\text{ nm}880 nm
