Limits Continuity And Differentiability

Let \(f(x) = \left\{ {\matrix{ {{x^3} - {x^2} + 10x - 7,} & {x \le 1} \cr { - 2x + {{\log }_2}({b^2} - 4),} & {x > 1} \cr } } \right.\).

Then the set of all values of b, for which f(x) has maximum value at x = 1, is :