a>b>o,求证2^(1/2)*a^3+3/(ab-b^2)>=10

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a>b>o,求证2^(1/2)*a^3+3/(ab-b^2)>=10

a>b>o,求证2^(1/2)*a^3+3/(ab-b^2)>=10
a>b>o,求证2^(1/2)*a^3+3/(ab-b^2)>=10

a>b>o,求证2^(1/2)*a^3+3/(ab-b^2)>=10
题目是求证:√2a^3+3/(ab-b^2)≥10 由a>b>0可得0=5*(√2/2a^3*√2/2a^3*(4/(a^2))*(4/(a^2)*(4/(a^2))^(1/5) =5*(1/2*4*4*4)^(1/5) =5*2 =10 等号成立当且仅当√2/2a^3=4/a^2,a=(4√2)^(1/5).② 由①②原不等式成立,等号成立当且仅当a=(4√2)^(1/5),b = a/2