μ λ = sin a + d λ / 2 {\displaystyle \mu \lambda =\sin {a+d\lambda /2}}
μ λ = sin ( A + D λ 2 ) sin ( A 2 ) {\displaystyle \mu _{\lambda }={\sin({A+D_{\lambda } \over 2}) \over \sin({A \over 2})}}
