\[\boxed{\mathbf{1000}\mathbf{.}}\]
\[1)\ a = 2,\ \ \ b = 4:\]
\[\ f(x) = x^{3}\]
\[F(x) = \frac{x^{4}}{4} + C.\]
\[S = \int_{2}^{4}{x^{3}\text{\ dx}} = F(4) - F(2) =\]
\[= \frac{4^{4}}{4} - \frac{2^{4}}{4} = \frac{256 - 16}{4} = \frac{240}{4} =\]
\[= 60.\]
\[Ответ:\ \ 60.\]
\[2)\ a = 3,\ \ \ b = 4:\text{\ \ }\]
\[f(x) = x^{2}\]
\[F(x) = \frac{x^{3}}{3} + C.\]
\[S = \int_{3}^{4}{x^{2}\text{\ dx}} = F(4) - F(3) =\]
\[= \frac{4^{3}}{3} - \frac{3^{3}}{3} = \frac{64 - 27}{3} = \frac{37}{3} =\]
\[= 12\frac{1}{3}.\]
\[Ответ:\ \ 12\frac{1}{3}.\]
\[3)\ a = - 2,\ \ \ b = 1:\text{\ \ }\]
\[f(x) = x^{2} + 1\]
\[F(x) = \frac{x^{3}}{3} + \frac{x^{1}}{1} = \frac{x^{3}}{3} + x + C.\]
\[S = \int_{- 2}^{1}{\left( x^{2} + 1 \right)\text{\ dx}} =\]
\[= F(1) - F( - 2);\]
\[S = \frac{(1)^{3}}{3} + 1 - \frac{( - 2)^{3}}{3} + 2 =\]
\[= \frac{1}{3} + \frac{8}{3} + 3 = 3 + 3 = 6.\]
\[Ответ:\ \ 6.\]
\[4)\ a = 0,\ \ \ b = 2:\ \]
\[f(x) = x^{3} + 1\]
\[F(x) = \frac{x^{4}}{4} + \frac{x^{1}}{1} = \frac{x^{4}}{4} + x + C.\]
\[S = \int_{0}^{2}{\left( x^{3} + 1 \right)\text{\ dx}} =\]
\[= F(2) - F(0);\]
\[S = \frac{2^{4}}{4} + 2 - \frac{0^{4}}{4} - 0 = \frac{16}{4} + 2 =\]
\[= 4 + 2 = 6.\]
\[Ответ:\ \ 6.\]
\[5)\ a = \frac{\pi}{3},\ \ \ b = \frac{2\pi}{3}:\]
\[f(x) = \sin x\]
\[F(x) = - \cos x + C.\]
\[S = \int_{\frac{\pi}{3}}^{\frac{2\pi}{3}}{\sin x\text{\ dx}} =\]
\[= F\left( \frac{2\pi}{3} \right) - F\left( \frac{\pi}{3} \right);\]
\[S = - \cos\frac{2\pi}{3} + \cos\frac{\pi}{3} =\]
\[= - \left( - \frac{1}{2} \right) + \frac{1}{2} = \frac{1}{2} + \frac{1}{2} = 1.\]
\[Ответ:\ \ 1.\]
\[6)\ a = - \frac{\pi}{6},\ \ \ b = 0:\ \ \]
\[f(x) = \cos x\]
\[F(x) = \sin x + C.\]
\[S = \int_{- \frac{\pi}{6}}^{0}{\cos x\text{\ dx}} =\]
\[= F(0) - F\left( - \frac{\pi}{6} \right);\]
\[S = \sin 0 - \sin\left( - \frac{\pi}{6} \right) =\]
\[= 0 + \sin\frac{\pi}{6} = \frac{1}{2}.\]
\[Ответ:\ \ \frac{1}{2}.\]