m+m分之1=2,m的平方+m的平方分之1=(m+1/m)²-2=4-2=2
m+1/m=2则(m+1/m)^2=4m^2+1/m^2+2*m*1/m=4m^2+1/m^2+2=4m^2+1/m^2=4-2m^2+1/m^2=2
m+1/m=2两边同时乘以mm²+1=2mm²-2m+1=0(m-1)²=0m=1m²+1/m=1*1+1/1=2
m²+1/m²=﹙m+1/m﹚²-2=2²-2=2
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