Light, of wavelength 649.3 nm, illuminates a single slit of unknown width. The 4ᵗʰ dark fringe is at an angle of 12.50 degrees with respect to the center a) Find the angles of the first three dark fringes with respect to the center b) If the wavelength of the light is doubled and the screen is 2.50 m away, what is the distance from the center to the first dark fringe? (assume small angle)