µ1sini=µ2sinr As incident vector A makes i angle with normal z-axis \& refracted vector R makes r angle with normal z - axis with help of direction cosine i=cos−1(
Az
A
)=cos−1(
5
√(4√3)2+(3√3)2+52
) =cos−1(
5
10
)⇒i=60∘ √2sin60=√3×sinr r=45∘ Difference between i&r=60−45=15