use grade 12 uni level physics

Question 13 ( 3 points) Light from a medium with index of refraction n1=2.12 passes into a medium with index of refraction n2=1.28. What is the critical angle where incoming light would all reflect off of the boundary, without passing into the second medium? Answer in degrees, , measured from the normal. Attach your work for full marks. Answers within 3% of the true answer will be considered to be correct. Your Answer: Answer units