解:(1)由log<x>(5x^2-8x+3)可知5x^2-8x+3>0x>0解得x>1或0<x<3/5当x>1时,log<x>(5x^2-8x+3)单调增log<x>(5x^2-8x+3)>2=log<x>x^2则5x^2-8x+3>x^2解得:x>3/2当0<x<3/5时,log<x>(5x^2-8x+3)单调减log<x>(5x^2-8x+3)>2=log<x>x^2则5x^2-8x+3<x^2解得:1/2<x<3/5综上所述:集合A={x|x>3/2,或1/2<x<3/5}2^(x^2-2x-k^4)>=1/2=2^(-1)因为2^(x^2-2x-k^4)单调增所以x^2-2x-k^4≥-1解得:x≥k^2+1或x≤1-k^2所以集合B={x|x≥k^2+1或x≤1-k^2}(2)如果A包含于B，求实数k的取值范围由于k^2+1≥1,1-k^2≤1所以如果A包含于B,则k^2+1≤3/2且1-k^2≥3/5解得:-√10/5≤k≤√10/5