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Find w2 maximizing (w2)TSw2 (w2)Tw2 1 (w2)Tw1 =0 g(w2)=(w2)TSw2-Q(w2)Tw2-1)-B(w2)Tw1-0) 0g(w2)/0w=0 Sw2-aw2-Bw1=0 0 -a0-B1โ˜ =0 wwd(w =w2)TSw1=1(w2)Tw1=0 Sw1=Aiw1 B=0:Sw2-aw2=0 Sw2=aw2 w2 is the eigenvector of the covariance matrix S Corresponding to the 2nd largest eigenvalue 12Find ๐‘ค2 maximizing ๐‘ค2 ๐‘‡๐‘†๐‘ค2 ๐‘ค2 ๐‘‡๐‘ค2 = 1 ๐‘ค2 ๐‘‡๐‘ค1 = 0 ๐‘” ๐‘ค2 = ๐‘ค2 ๐‘‡๐‘†๐‘ค2 โˆ’ ๐›ผ ๐‘ค2 ๐‘‡๐‘ค2 โˆ’ 1 โˆ’๐›ฝ ๐‘ค2 ๐‘‡๐‘ค1 โˆ’ 0 ๐œ•๐‘” ๐‘ค ฮค 2 ๐œ•๐‘ค1 2 = 0 ๐œ•๐‘” ๐‘ค ฮค 2 ๐œ•๐‘ค2 2 = 0 โ€ฆ ๐‘†๐‘ค2 โˆ’ ๐›ผ๐‘ค2 โˆ’ ๐›ฝ๐‘ค1 = 0 ๐‘ค1 ๐‘‡๐‘†๐‘ค2 โˆ’ ๐›ผ ๐‘ค1 ๐‘‡๐‘ค2 โˆ’ ๐›ฝ ๐‘ค1 ๐‘‡๐‘ค1 = 0 0 1 = ๐‘ค2 ๐‘‡๐‘†๐‘ค1 = ๐‘ค2 ๐‘‡๐‘† = ๐‘ค1 ๐‘‡ ๐‘‡๐‘ค1 ๐‘†๐‘ค2 ๐‘‡ = ๐œ†1 ๐‘ค2 ๐‘‡๐‘ค1 = 0 ๐›ฝ = 0: ๐‘†๐‘ค2 โˆ’ ๐›ผ๐‘ค2 = 0 ๐‘†๐‘ค2 = ๐›ผ๐‘ค2 ๐‘ค2 is the eigenvector of the covariance matrix S Corresponding to the 2nd largest eigenvalue ๐œ†2 0 ๐‘†๐‘ค1 = ๐œ†1๐‘ค1
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