Question

Use four rectangles to approximate the area under the graph of f(x) = 2x+3 and above
the x-axis from x = 0 to x = 4. Let the height of each rectangle be the function value on the
right side.
1

Answer 1

your partition would be:
\[ \large x_0=0\quad x_1=1\quad x_2=2\quad x_3=3\quad x_4=4 \]

Answer 2

the Riemann's sum would be
\[ \large \sum_{i=1}^4f(x_i)\cdot\Delta x_i \]