1. The diagram below shows a ray of light passing straight through the longest side of the right-angled isosceles triangular prism. Upon impact with one of the other smaller sides of the prism, the light ray is reflected towards the third side before being reflected for the final time to pass straight back out of the longest side.

What is the smallest ratio of the refractive index of the medium that the light enters the prism from n_o to the ratio of the refractive index of the prism n_p that will cause the ray of light to totally internally reflect?