Known: 0 〈 a 〈 1, proof: 1 / a 4 / (1-A) greater than or equal to 9

Analysis method;
1/a 4/(1-a)=4/a(1-a)>=9
4/9

RELATED INFORMATIONS

1. It is proved that if a, B ∈ R, then at least one of a ^ 2 + AB and B ^ 2 + AB is non negative Good answer points
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