Verified answer

Решение.

[tex]\displaystyle S=\int\limits_1^2\, x^2\, dx=\frac{x^3}{3}\ \Big|_1^2=\frac{2^3}{3}-\frac{1^3}{3}=\frac{8}{3}-\frac{1}{3}=\frac{7}{3}[/tex]