Example 2.83. The conductor has the shape of a truncated cone. The diameter of its arbitrary cross-section, located at a distance $x$ from the smaller cross-section, is $y=a+\frac{x(b-a)}{h}$, where $a$ is the diameter of the smaller, and $b$ is the diameter of the larger cross-section, $h$ is the height of the cone. Knowing the specific resistance $\rho$ and the formula for calculating the elementary resistance $d R=\rho \frac{d x}{S(x)}$, where $S(x)$ is the cross-sectional area, find the total resistance $R$.