Fresnel coefficients

1. Nov 13, 2013

Dassinia

Hello,
1. The problem statement, all variables and given/known data[/b]

http://imageshack.com/a/img17/2531/gu44.png [Broken]Uploaded with ImageShack.com
I'm trying to prove this but i didn't succeed
2. Relevant equations

3. The attempt at a solution
For the t I multiplied by sin(θt) in the numerator and denominator and used
sin(a) * cos(b) = 1/2 × (sin(a+b) + sin(a-b))
I ended with a 4cos(θt)sin(θi)/[sin(θi+θt)+sin(θt-θi)] but then ?
For r I don't even know how to start

Thanks

Last edited by a moderator: May 6, 2017
2. Nov 13, 2013

ehild

ehild

That is all right, but use Snell's Law nisin(θi)=ntsin(θt) after, and see if you can simplify...

ehild

Last edited by a moderator: May 6, 2017
3. Nov 13, 2013

Dassinia

and for r, how can I start

4. Nov 13, 2013

ehild

The same way.

ehild