Gradients 。Because: (x-x)广+(x-x)上+(g-x)=0 w=U-D+u-月 2AT 2AT f Xi Consistent with the formula in the book. X xj Gradients • Because: 𝒙𝑘 − 𝒙𝑗 ⊥ + 𝒙𝑖 − 𝒙𝑘 ⊥ + 𝒙𝑗 − 𝒙𝑖 ⊥ = 0 => 𝛻𝒙𝑓 𝒙 = 𝑓𝑗 − 𝑓𝑖 𝒙𝑖 − 𝒙𝑘 ⊥ 2𝐴𝑇 + (𝑓𝑘 − 𝑓𝑖) 𝒙𝑗 − 𝒙𝑖 ⊥ 2𝐴𝑇 • Consistent with the formula in the book. 𝑓𝑖 𝑓𝑗 𝑓𝑘 𝒙𝑗 𝒙𝑘 𝒙𝑖 𝒙