Ln x = ax has several real roots (a > 0)

Ln x = ax has several real roots (a > 0)

Let f (x) = LNX ax, then f '(x) = 1 / x-a,
Let f '(x) = 0, then x = 1 / A
When x belongs to (0,1 / a), f '(x) > 0; when x belongs to (1 / A, + infinity), f' (x) 0, then 0