In the formation of a rainbow light is incident on raindrops from the sun, and then this light is reflected and emerges from the rain drops at approximately 42 degrees. In other words, if you look at the arch of a rainbow it is at an angle of 42 degrees with respect to the direction that you would look towards the shadow of your head. What is the difference between the angles that the red and blue light will emerge from the raindrop, taking the refractive index of water to be 1.33007 and 1.34287 for red and blue light, respectively? You will need to prove that the angle is roughly 42 degrees, and more precisely find how this angle changes slightly for different colors which are what gives the rainbow its cool colors.