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$$\frac{2 \left(- 4 \log{\left(x \right)} + \frac{6 \left(x + 3\right) \log{\left(x \right)}}{x} + 2 - \frac{5 \left(x + 3\right)}{x}\right)}{x^{3}} = 0$$
Solve this equationThe roots of this equation
$$x_{1} = 43847.5905884662$$
$$x_{2} = 53841.952602536$$
$$x_{3} = 31502.6420619197$$
$$x_{4} = 34886.2640297897$$
$$x_{5} = 52735.3601050521$$
$$x_{6} = 33759.938295641$$
$$x_{7} = 2.68147262116116$$
$$x_{8} = 32632.0827716515$$
$$x_{9} = 57156.4807890037$$
$$x_{10} = 30371.5579010177$$
$$x_{11} = 48299.6168667142$$
$$x_{12} = 36011.1126055766$$
$$x_{13} = 40496.6981287632$$
$$x_{14} = 49410.0091923193$$
$$x_{15} = 44962.2264158991$$
$$x_{16} = 50519.4130981396$$
$$x_{17} = 54947.6556019799$$
$$x_{18} = 47188.2084874369$$
$$x_{19} = 37134.5340105345$$
$$x_{20} = 46075.7551136742$$
$$x_{21} = 51627.8549875932$$
$$x_{22} = 41614.8623757666$$
$$x_{23} = 39377.2828114816$$
$$x_{24} = 38256.5757166382$$
$$x_{25} = 42731.8142563409$$
$$x_{26} = 56052.4912533661$$
You also need to calculate the limits of y '' for arguments seeking to indeterminate points of a function:
Points where there is an indetermination:
$$x_{1} = 0$$
$$\lim_{x \to 0^-}\left(\frac{2 \left(- 4 \log{\left(x \right)} + \frac{6 \left(x + 3\right) \log{\left(x \right)}}{x} + 2 - \frac{5 \left(x + 3\right)}{x}\right)}{x^{3}}\right) = -\infty$$
Let's take the limit$$\lim_{x \to 0^+}\left(\frac{2 \left(- 4 \log{\left(x \right)} + \frac{6 \left(x + 3\right) \log{\left(x \right)}}{x} + 2 - \frac{5 \left(x + 3\right)}{x}\right)}{x^{3}}\right) = -\infty$$
Let's take the limit- limits are equal, then skip the corresponding point
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
$$\left[2.68147262116116, \infty\right)$$
Convex at the intervals
$$\left(-\infty, 2.68147262116116\right]$$