Hallemos los puntos de flexiones, para eso hay que resolver la ecuación
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = 0$$
(la segunda derivada es igual a cero),
las raíces de la ecuación obtenida serán los puntos de flexión para el gráfico de la función indicado:
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = $$
segunda derivada$$2 \sqrt{x} \left(\tan^{2}{\left(x \right)} + 1\right) \tan{\left(x \right)} + \frac{\tan^{2}{\left(x \right)} + 1}{\sqrt{x}} - \frac{\tan{\left(x \right)}}{4 x^{\frac{3}{2}}} = 0$$
Resolvermos esta ecuaciónRaíces de esta ecuación
$$x_{1} = 2.97267489465031$$
$$x_{2} = 9.37139905890989$$
$$x_{3} = 56.5398243251235$$
$$x_{4} = -87.9589097974476$$
$$x_{5} = 100.52599105631$$
$$x_{6} = 87.9589097974476$$
$$x_{7} = -53.397711277025$$
$$x_{8} = -59.6818825684128$$
$$x_{9} = 91.1006984944297$$
$$x_{10} = 50.2555331401204$$
$$x_{11} = 78.5334495829027$$
$$x_{12} = -50.2555331401204$$
$$x_{13} = -40.8284578305388$$
$$x_{14} = 6.2024870457813$$
$$x_{15} = -84.8171065755666$$
$$x_{16} = -9.37139905890989$$
$$x_{17} = -78.5334495829027$$
$$x_{18} = 15.6760621125375$$
$$x_{19} = -81.6752871523214$$
$$x_{20} = -56.5398243251235$$
$$x_{21} = 37.6858438726898$$
$$x_{22} = -72.2497105343831$$
$$x_{23} = 65.965865975172$$
$$x_{24} = -47.1132768850395$$
$$x_{25} = -2.97267489465031$$
$$x_{26} = -18.8229895430946$$
$$x_{27} = 43.9709257551348$$
$$x_{28} = 40.8284578305388$$
$$x_{29} = -12.5264445146365$$
$$x_{30} = 21.9683866353213$$
$$x_{31} = -25.112829773268$$
$$x_{32} = -28.2566380026491$$
$$x_{33} = -65.965865975172$$
$$x_{34} = 12.5264445146365$$
$$x_{35} = -91.1006984944297$$
$$x_{36} = -6.2024870457813$$
$$x_{37} = 53.397711277025$$
$$x_{38} = -69.1078032428841$$
$$x_{39} = -97.3842379376276$$
$$x_{40} = 59.6818825684128$$
$$x_{41} = -43.9709257551348$$
$$x_{42} = -15.6760621125375$$
$$x_{43} = 18.8229895430946$$
$$x_{44} = 25.112829773268$$
$$x_{45} = -94.2424741193764$$
$$x_{46} = 75.3915915982233$$
$$x_{47} = 47.1132768850395$$
$$x_{48} = -62.8238942325121$$
$$x_{49} = -75.3915915982233$$
$$x_{50} = 94.2424741193764$$
$$x_{51} = 62.8238942325121$$
$$x_{52} = 72.2497105343831$$
$$x_{53} = -100.52599105631$$
$$x_{54} = 28.2566380026491$$
$$x_{55} = -37.6858438726898$$
$$x_{56} = -31.4000022978176$$
$$x_{57} = 97.3842379376276$$
$$x_{58} = 81.6752871523214$$
$$x_{59} = -21.9683866353213$$
$$x_{60} = 84.8171065755666$$
$$x_{61} = 31.4000022978176$$
$$x_{62} = 34.5430439901451$$
$$x_{63} = -34.5430439901451$$
$$x_{64} = 69.1078032428841$$
Intervalos de convexidad y concavidad:Hallemos los intervales donde la función es convexa o cóncava, para eso veamos cómo se comporta la función en los puntos de flexiones:
Cóncava en los intervalos
$$\left[100.52599105631, \infty\right)$$
Convexa en los intervalos
$$\left(-\infty, 2.97267489465031\right]$$