We want to compute the area between the curve {{MATH_8}} and the horizontal axis on the interval {{MATH_9}}: {{CMD_10}} {{ENV_11}} {{CMD_12}} One way to do this would be to approximate the area with rectangles. With one rectangle we get a rough approximation: {{CMD_13}} {{ENV_14}} {{CMD_15}} Two rectangles might make a better approximation: {{CMD_16}} {{ENV_17}} {{CMD_18}} With even more, we get a closer, and closer, approximation: {{CMD_19}} {{ENV_20}} {{CMD_21}}