\[\boxed{\mathbf{29}.}\]
\[\textbf{а)}\ y = x + 1;\ \ \lbrack 0;1\rbrack\]
\[S = \left( \underset{\text{n\ }слагаемых}{\overset{0 + \frac{1}{n} + \frac{2}{n} + \ldots + \frac{n - 1}{n}}{︸}} \right) \cdot \frac{1}{n};\]
\[S_{1} = 0 \cdot \frac{1}{1} + 1 = 1;\]
\[S_{2} = \left( 0 + \frac{1}{2} \right) \cdot \frac{1}{2} + 1 = 1,25;\]
\[S_{3} = \left( 0 + \frac{1}{3} + \frac{2}{3} \right) \cdot \frac{1}{3} + 1 = 1\frac{1}{3};\]
\[S_{4} = \left( 0 + \frac{1}{4} + \frac{2}{4} + \frac{3}{4} \right) \cdot \frac{1}{4} + 1 =\]
\[= 1\frac{3}{8}.\]
\[= \frac{\frac{n - 1}{n}}{2} + 1 = \frac{n - 1}{2n} + 1 =\]
\[= \frac{3n - 1}{2n};\]
\[\lim_{n \rightarrow \infty}S_{n} = \lim_{n \rightarrow \infty}\frac{3n - 1}{2n} = \frac{3}{2} = 1,5.\]
\[Да,\ существует.\]
\[\textbf{в)}\ S_{n} = \frac{3n - 1}{2n};\]
\[\lim_{n \rightarrow \infty}S_{n} = \lim_{n \rightarrow \infty}\frac{3n - 1}{2n} = \frac{3}{2} = 1,5;\]
\[Площадь\ фигуры\ и\ есть\ предел\ \]
\[интегральной\ суммы:\]
\[S_{фигуры} = 1,5.\]