Calculating Root Mean Square

[ssw513]

how do you calculate the root mean square of the function i = 15(1 - e ^ -0.5t) from t = 0 to t = 4

 

[royhaas]

Square the function, integrate it over the interval, divide by the length of the interval, and take the square root.

 

[ssw513]

you divide by the length of interval BEFORE taking the square root? I am having difficulty solving this problem.....any help would be greatly appreciated....thanks

 

[ssw513]

I squared the function to get 225 (1 - 2e^-0.5t +e^ -t)
Then integrated to get -2 * 225 [u - 2e^u + e ^2u] du
I do not think my integration is right and I can't figure out how to do the different powers of e?
Do I divide this by 4 and then take the square root or vice versa?