Let's find the inflection points, we'll need to solve the equation for this
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = 0$$
(the second derivative equals zero),
the roots of this equation will be the inflection points for the specified function graph:
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = $$
the second derivative$$\frac{48 \cdot \left(2 - \log{\left(4 x - 3 \right)}\right) \log{\left(4 x - 3 \right)}}{\left(4 x - 3\right)^{2}} = 0$$
Solve this equationThe roots of this equation
$$x_{1} = 1$$
$$x_{2} = \frac{3}{4} + \frac{e^{2}}{4}$$
Сonvexity and concavity intervals:Let’s find the intervals where the function is convex or concave, for this look at the behaviour of the function at the inflection points:
Concave at the intervals
$$\left[1, \frac{3}{4} + \frac{e^{2}}{4}\right]$$
Convex at the intervals
$$\left(-\infty, 1\right] \cup \left[\frac{3}{4} + \frac{e^{2}}{4}, \infty\right)$$