- #1

s3a

- 818

- 8

## Homework Statement

The problem and its solution are attached as TheProblemAndSolution.png.

## Homework Equations

Integration

P = VI

V = RI

## The Attempt at a Solution

I think Wolfram Alpha “says” ( http://www.wolframalpha.com/input/?i=integrate+900sin^2(377t)+dt+from+0+to+pi ) that the equation should be the way it is with a dt rather than a d(377t).

I think I get why the limits of integration are 0 to π rather than 0 to 2π (I'm guessing it's because we're taking the average – which is (0+2π)/2 = π) but, I'm having trouble with the following.:

(1) How am I supposed to know to multiply by 1/π?

(2) Is the p_(avg) equation supposed to have dt instead of d(377t)?

(3) Is it a fluke that the limits of integration have been from 0 to 2π and then divided by 2 to get the same answer?

I might have more questions that arise as I get these answered but, I am not sure yet.

Any help would be greatly appreciated!