Let f (x) = - 2x ^ 2 + 7X-2, for real number m (0 < m < 7 / 4), if the domain of definition and value of F (x) are [M, 3] and [1,3 / M] respectively, what is the value of M?

Let f (x) = - 2x ^ 2 + 7X-2, for real number m (0 < m < 7 / 4), if the domain of definition and value of F (x) are [M, 3] and [1,3 / M] respectively, what is the value of M?

F (x) = - 2x ^ 2 + 7X-2, where a = - 2, B = 7, C = - 2
a