# Thread: Average Rate of Change Calc!!

1. ## Average Rate of Change Calc!!

OK how do i solve this? I am completely lost even how to approach it. A explanation/step by step method is desired. I am extremely grateful for any help!

y=2x(sin2x+xcos2x)
interval 0 less than or equal to x less than or equal to pi/2
What is the average rate of change of y wiht respect to x in this interval?

2. Originally Posted by painterchica16
OK how do i solve this? I am completely lost even how to approach it. A explanation/step by step method is desired. I am extremely grateful for any help!

y=2x(sin2x+xcos2x)
interval 0 less than or equal to x less than or equal to pi/2
What is the average rate of change of y wiht respect to x in this interval?
Let $y = f(x)$

so, $f(x) = 2x( \sin 2x + x \cos 2x)$

the average rate of change between $x = 0$ and $x = \frac {\pi}2$ is given by

$\text{Average rate of change} = \frac {f \bigg( \frac {\pi}2 \bigg) - f(0)}{\frac {\pi}2 - 0}$

that is a general formula that you should know. look it up in your text. if they ask for "average rate of change", that's the formula they want you to use