c = w → ⋅ 1 2 ( μ → 0 + μ → 1 ) = 1 2 μ → 1 T Σ − 1 μ → 1 − 1 2 μ → 0 T Σ − 1 μ → 0 {\displaystyle c={\vec {w}}\cdot {\frac {1}{2}}({\vec {\mu }}_{0}+{\vec {\mu }}_{1})={\frac {1}{2}}{\vec {\mu }}_{1}^{T}\Sigma ^{-1}{\vec {\mu }}_{1}-{\frac {1}{2}}{\vec {\mu }}_{0}^{T}\Sigma ^{-1}{\vec {\mu }}_{0}} .