Thread: Simple integration please help

Integrate x + pi dx between pi and -pi

thanks

Originally Posted by adam_leeds

Integrate x + pi dx between pi and -pi

If you want help with a calculus problem, don't put it in the pre-calculus section!

So, what's the difficulty? The integral of x is , the integral of (being a constant) is . Add them together, evaluate the result at and , and take the difference.

To solve the integral, raise x to the second power and divide it by 2, and add an x to pi to get:

(2x)/2 + pi(x) + C

Now just solve the integral for pi to -pi, so you would just sub in and solve by subtracting the second number solved in the indefinite integral, minus the first.

((2pi)/2 + pi(pi)) - ((2(-pi)/2 + pi(-pi))

(4pi)/2 + 2(pi)^2

Originally Posted by NRS

To solve the integral, raise x to the second power and divide it by 2, and add an x to pi to get:

(2x)/2 + pi(x) + C

You just said "raise x to the second power" but now you write "2x"!
That should be

Now just solve the integral for pi to -pi, so you would just sub in and solve by subtracting the second number solved in the indefinite integral, minus the first.

((2pi)/2 + pi(pi)) - ((2(-pi)/2 + pi(-pi))

(4pi)/2 + 2(pi)^2

And apparently that was not just a typo since you now calculate 2 times pi rather than squareing. You should have

Sorry, I must have made the typo, then calculated according to it. Should do better checking my work, sorry.