已知x>0，y>0，x+y=1，n∈N*，求证：x2n+y2n≥122n-1．
举一反三
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- Consider the following sequence: x(n)={3,-6,5,-1,0,7,8}, -1≤n≤5.suppose the sequence y(n)=x(-n-2),then y(0)=______ , y(-2)=______ , y(-4)=______ , y(-6)=______ , y(2)=______ .