Recent content by Jules18

Really? the equality I posted is straight from my prof's answer key. ... Also, I'm not sure I understand what you mean by cosh^2(t). Is that another way of expressing cos^2(ht)? In that case I thought cos^2(x) + sin^2(x) = 1, so how could cos^2(x) - 1 = sin^2(x) ? I was thinking it...

I'm sorry about the latex. I edited it but the changes aren't showing up. Hope you can still decipher it. The latex program is ridiculously glitchy, but I'm sure I'm not the first person to say that.

\int\stackrel{du}{\sqrt{u^{2}-4}} = ln(u + sqrt.(u2-4)) My answer key makes the jump directly from that integral to that natural log fxn, which would make sense to me if only the "u +" weren't inside the brackets of the ln fxn. Does anyone know where it comes from?

Thanks for the replies, guys. The article is actually from this page: http://www.fossils-facts-and-finds.com/how_are_fossils_formed.html The excerpt is under the second subtitle.

I found this in an article about fossilization and it kind of scared me - doesn't this remind you of the movie The Day After Tomorrow?

hm okay well I was given this question on an exam, so I figure my prof had a different approach in mind. Is there a simpler way?

I understand up to = \lim_{x\to 0^+} \frac{-x+{x^3\over 3!}-\cdots}{2x(1-{x^2\over 2!}\cdots)} . I really lost you on that one. Why would that be equal to lim -Sinx/(2xCosx) ??

Really? I always thought the limit of 1/(x2) would be infinite when x approaches 0.

Limit as x-->0+ Homework Statement lim (Cosx)1/(x2) x-->0+ The Attempt at a Solution I figured 1/x2 would approach infinity, which and Cos0=1, so the function would approach 1\infty which is \infty, but I was wrong and I got no marks at all for this question. Any help at all...

ok I get it. the limits are missing, it must be a typo, but otherwise this makes sense to me now thanks

Hey guys, I've tried this question a couple different ways. Please help! Homework Statement Calculate the concentration of the acetate ion (M) in a solution prepared by dissolving 1.00×10-3 mol of HCl(g) in 1.00 L of 1.90 M aqueous acetic acid. Ka = 1.7E-5 And at that point I'm not...

jakncoke, by Exp[x] do you mean ex where e is the constant that's approx. 2.718 ?

Homework Statement True or false? lim Tanx/(1-Cosx) = lim Sec2x/Sinx = Infinity (limits are as x approaches \pi from the left) The Attempt at a Solution I tried just plugging \pi into x in the first limit, and I ended up getting 0/2, which exists but is just 0. So...

Homework Statement True or false? ln(1/10) = -\int dx/x The Attempt at a Solution I have no idea where to start on this one. what is dx/x ??

Homework Statement True or false? Cosh x > 1 for all x The Attempt at a Solution the answer is true, and I'm not sure why. if h is a coefficient, then I'm pretty sure I can think of some values of x and h that would be < 1. For instance, if h=1 and x=\pi/3 What does the...