Table 1.

Modeling of the reflection functions: Group L—dental pressed ceramics.

x	$\left[0,x_m\right)=\left[0,1.5\right)$	$\left[x_m,x_{\max }\right)=\left[1.5,3.25\right)$
ρ(x)	$f(x)=\frac{\left({\rho }_0-{\rho }_{\min }\right)}{x_m}\left(\frac{x^2}{x_m}-2x\right)+{\rho }_0$	$\begin{array}{l}g(x)=\frac{{\rho }_{\max }-{\rho }_{\min }}{{\left(x_{\max }-x_m\right)}^2}x\left(x-2x_m\right)+\\ +\frac{{\rho }_{\min }\left(x_{\max }-2x_m\right)x_{\max }-{\rho }_{\max }{x}_m^2}{{\left(x_{\max }-x_m\right)}^2}\end{array}$
	$f(x)=11.11x^2-33.33x+60$	$g(x)=15.35x^2-16.33x+69.53$
dρ/dx	$f^{\prime }(x)=2\frac{\left({\rho }_0-{\rho }_{\min }\right)}{x_m}\left(\frac{x}{x_m}-1\right)$	$g^{\prime }(x)=2\frac{{\rho }_{\max }-{\rho }_{\min }}{{\left(x_{\max }-x_m\right)}^2}\left(x-x_m\right)$
	$f^{\prime }(x)=22.22\cdot x-33.33$	$g^{\prime }(x)=30.7\cdot x-16.33$
d2ρ/dx2	$f^{″}(x)=2\frac{\left({\rho }_0-{\rho }_{\min }\right)}{x_m^2}=22.22{\mathrm{mm}}^{-2}$	$g^{″}(x)=2\frac{{\rho }_{\max }-{\rho }_{\min }}{{\left(x_{\max }-x_m\right)}^2}=30.7{\mathrm{mm}}^{-2}$