if a,b belong to ]-1,2] the following equation holds true
[tex] log_{ \frac{2}{3} }( \frac{2 - a}{3} ) \times log_{ \frac{2}{3} }( \frac{1 + b}{3} ) = 1[/tex]
what if the minimal value that the following could have:
E=ab+a-2ab
