Table 3.

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

x	$\left[0,x_i=2x_M\right)=\left[0,1.4\right)$	$\left[x_i,x_{\max }\right)=\left[1.4,3.25\right)$
ρ(x)	$f(x)=\frac{{\rho }_{\max }-{\rho }_0}{x_M}\left(-\frac{x^2}{x_M}+2x\right)+{\rho }_0$	$\begin{array}{l}g(x)=\frac{{\rho }_0-{\rho }_{\min }}{{\left(2x_M-x_m\right)}^2}x\left(x-2x_m\right)+\\ +\frac{{\rho }_0{x}_m^2+4{\rho }_{\min }\left(2x_m-x_M\right)x_M}{{\left(2x_M-x_m\right)}^2}\end{array}$
	$f(x)=30.61x^2-42.85x+60$	$g(x)=23.12x^2-107.76x+170.5$
dρ/dx	$f^{\prime }(x)=2\frac{{\rho }_{\max }-{\rho }_0}{x_m}\left(-\frac{x}{x_M}+1\right)$	$g^{\prime }(x)=2\frac{{\rho }_o-{\rho }_{\min }}{{\left(2x_M-x_m\right)}^2}\left(x-x_m\right)$
	$f^{\prime }(x)=61.22\cdot x-42.85$	$g^{\prime }(x)=46.24\cdot x-107.76$
d2ρ/dx2	$f^{″}(x)=-2\frac{\left({\rho }_{\max }-{\rho }_0\right)}{x_m{x}_M}=30.61{\mathrm{mm}}^{-2}$	$g^{″}(x)=2\frac{{\rho }_0-{\rho }_{\min }}{{\left(2x_M-x_m\right)}^2}=46.24{\mathrm{mm}}^{-2}$