20 15 W1 W2 y →夕 106 =1 0.5 o L=(⊙-w1w2x)2=(1-w1w2)2 15 2.0 .0 -15 -10 -0.5 0.0 05 10 15 0W1 2(1-w1w2)(-w2) Critical point: W1=0,W2=0 =0 aL H=[9201a=22=-2 0W2 2(1-w1w2)(-w1) Saddle point =0 021 2(-w2)(-w2) 02L 0w1 -2+4W1W2 H =0 0w1∂w, =-2 02L -2+4W1W2 0w20W1 2(-w1)(-w1) =-2 =0𝐿 = 𝑦 ො − 𝑤1𝑤2𝑥 2 𝜕𝐿 𝜕𝑤1 = 2 1 − 𝑤1𝑤2 −𝑤2 𝜕𝐿 𝜕𝑤2 = 2 1 − 𝑤1𝑤2 −𝑤1 𝜕 2𝐿 𝜕𝑤1 2 = 2 −𝑤2 −𝑤2 𝜕 2𝐿 𝜕𝑤2 2 = 2 −𝑤1 −𝑤1 𝜕 2𝐿 𝜕𝑤1𝜕𝑤2 = −2 + 4𝑤1𝑤2 𝜕 2𝐿 𝜕𝑤2𝜕𝑤1 = −2 + 4𝑤1𝑤2 𝑤1 𝑤2 𝑥 𝑦 𝑦 ො = 1 = 1 = 1 − 𝑤1𝑤2 2 Critical point: 𝑤1 = 0, 𝑤2 = 0 𝐻 = 0 −2 −2 0 𝜆1 = 2, 𝜆2 = −2 Saddle point = 0 = 0 = 0 = −2 = 0 = −2 𝒈 𝐻