Snells law -- help please A light ray approaches a glass block at 30° to the normal. The refractive indices of air and water are 1 and 1.5 respectively At what angle will the light be refracted? This uses Snells law I did Sin 30 / Sin r = 1 / 1.5 I then multiplied both sides in order to get rid of sin 30. After that, I got Sin r = 1/1.5(xSin30) This gave me an answer of -1.48 When I do inverse sine it gives me an error What did I do wrong???