Let {{MATH_113}} be continuous on {{MATH_114}}. The {{CMD_115}} of {{MATH_116}} on {{MATH_117}} is given by {{MATH_118}} {{CMD_119}} Multiplying this equation by {{MATH_120}}, we obtain that {{MATH_121}} If {{MATH_122}} is positive, the average value of a function gives the height of a single rectangle whose area is equal to {{MATH_123}} {{CMD_124}} {{ENV_125}} {{CMD_126}}