Jawabanmu

2014-02-16T17:18:40+07:00
I = sudut datang
r = sudut bias
n1 = nu
n2 = na

 \frac{n_2}{n_1} = \frac{sini}{sinr}

 \frac{4}{3} =  \frac{sin30}{sinr}

sinr =  \frac{3}{4} ( \frac{1}{2} )

sinr =  \frac{3}{8}

r = (sekitar) 22 derajat
*pake kalkulator buat ngitung r, maaf :v

CMIIW :3