B Refractive index, Snell's Law

1. Mar 31, 2016

Gajan1234

At the start of the chapter the book told me to use this formula to find refractive index: N= Sin(i)/Sin(r)
How ever later in the section they showed me to use this formula when three quantities are given : NxSin(i)=NxSin(r)
I tried apply the same method to a question, it gave me a wrong answer. Why is it?

2. Mar 31, 2016

Chandra Prayaga

Your second equation is not correct. You must understand what the symbols mean. What is i? What is r? What is Nx? Then the relation between the two equations you wrote will become clear.

3. Mar 31, 2016

Gajan1234

Thank you Chandra

4. Mar 31, 2016