Prove rms voltage using integration

[iamnew]

Homework Statement

ac voltage
v=sinx

Homework Equations

how do you prove that rms voltage is 0.707v using integration

The Attempt at a Solution

 

[Fightfish]

The root-mean-square value of a function is the root of the average of the square of the function.
The average of the square of a function f (x) over an interval is given by:

\frac{\int_{t_{1}}^{t_{2}} (f (x))^{2} dx}{t_{2} - t_{1}}​

You can do the relevant integration yourself for f (x) = sin x (or any sinusoidal function for that matter)