\[\boxed{\mathbf{47}.}\]
\[\textbf{а)}\ \int_{0}^{1}{x^{2}\text{dx}} = \left. \ \frac{x^{3}}{3} \right|_{0}^{1} = \frac{1^{3}}{3} - \frac{0^{3}}{3} =\]
\[= \frac{1}{3}.\]
\[\textbf{б)}\ \int_{- 1}^{1}{x^{2}\text{dx}} = \left. \ \frac{x^{3}}{3} \right|_{- 1}^{1} =\]
\[= \frac{1^{3}}{3} - \frac{( - 1)^{3}}{3} = \frac{2}{3}.\]
\[\textbf{в)}\ \int_{- 1}^{2}{x^{2}\text{dx}} = \left. \ \frac{x^{3}}{3} \right|_{- 1}^{2} =\]
\[= \frac{2^{3}}{3} - \frac{( - 1)^{3}}{3} = \frac{9}{3} = 3.\]