Can you please help me on the problems below? :(

A beam of initially unpolarized light passes through a sequence of three ideal polarizers. The angle d12 between the axes of the first and second polarizers is 23.1, and the angle 423 between the axes of the second and third polarizers is 54.5. P 12 (P 23 w What is the ratio of the intensity I3 of light emerging from the third polarizer to the intensity Io of light incident on the first polarizer? IoLight that has a 700nn1 wavelength is incident upon two narrow slits that are separated by 0.450 mm. An interference pattern from the slits is projected onto a screen that is 2.60 m away. What is the separation distance Dbl on the screen of the rst bright fringe from the central bright fringe? What is the separation distance Ddg on the screen of the second dark fringe from the central bright fringe