That's f'ing awesome. On a side note, you can use (u = X^2 + 1), (x^2 = u- 1) too. I was getting to step 10 and then was getting stuck. Kept thinking I wasn't getting the right answer because I wasn't simplifying all the way. Also, I can't order your stupid HP Lovecraft book if you don't have a shipping address.
Hey, Folken, how'd you turn your TeX into a gif? I tried searching for dvi2gif, but didn't find anything useful...
I'm using OS X to view the pdf in Preview and then just saving it as a GIF. But it would be fucking sweet if Ramius could code in LaTeX directly into the forums....
Posts
dx = sec^2(theta)d(theta)
Classic trig substitution problem.
As for your side note, I don't seem to get the same answer doing it that way, but at this hour I can't seem to see anything wrong with it necessarily.
I appreciate the offer, but no reimbursement is necessary on your end. The wish list is there as a remnant from the G&T Secret Santa.
Yeah, I definitely don't see this. Maybe it might simplify to the same answer at the end, but it definitely doesn't get you straight to step 6.
u^2 = x^2 + 1
=> u du = x dx
x^3 * sqrt(x^2 + 1) dx = x^2 * sqrt(x ^2 + 1) * x dx = (u^2 - 1) * sqrt(u^2) * u du = (u^2 - 1) u^2 du = u^4 - u^2 du
Is step 6.
Edit: Whoops, hit step 7 by mistake. Went one too far.
Well done sir.
I am SO disappointed.
You can always use ImageMagick's "convert" to change from postscript to gif, I believe.
I'm using OS X to view the pdf in Preview and then just saving it as a GIF. But it would be fucking sweet if Ramius could code in LaTeX directly into the forums....