Recent content by kemmy

Ah thank you. I finally managed to figure it out. dp/dx = [(e^x)+(e^-x)]/[((e^x)-(e^-x))^2] u=e^x - e^-x du= e^x - e^-x (-1) dx du= - e^x + e^-x dx I= 1/u^2 (du) I= u^-2 (du) I= -1 u^-1 I= 1/-u + c p= -1/( e^x - e^-x) + C Thanks for all the...

Thanks Dick, you're really helping me right now. I have a lot of trouble with math and so I'm getting very turned around on this problem. That said, I don't really understand your hint. I'm just getting really frustrated and confused with this. I'm going to try to go through it step for...

Thanks. Technically, for this exam I'm studying for, we're not supposed to know those hyperbolic functions- so I've got to make use of substitution. Okay, so: I split the derivative into the two parts:(e^x)[(e^x)-(e^-x)]^-2 and (e^-x)[(e^x)-(e^-x)]^-2 and made u=e^x so du=(e^x)dx and...

Homework Statement Find the antiderivative of each derivative: dp/dx = [(e^x)+(e^-x)]/[((e^x)-(e^-x))^2] The Attempt at a Solution I can't entirely figure out how to get myself started here. I tired splitting up the derivative so that it's [(e^x)/ (((e^x)-(e^-x))^2)] +...

Okay... that does make sense. Thanks. I get so confused with Limits working with infinity I just always manage to get myself turned around. Thanks for all the help!

Homework Statement Find the Limit (as x-> -infinity) of [(7x^2)-x+11]/(4-x) So I found that the limit is infinity/infinity indeterminate form so I tried to use L'hopital's to solve it. So I took the derivative of (7x^2)-x+11 and got 14x-1 then for the derivative of 4-x I got -1 So...

Ack! okay...I think I can remember to catch that u. Thanks so much for all your help!

Oh! I think I've got it... so 4+u/u to (4/u)+ (u/u) to 4(1/u)+(u/u) cancel out the u/u to equal 1 and turn it to 4ln|u|+x+c. right? Thanks for all the help!

Thanks. I just tried that, and it helped a little- but I'm still getting the wrong answer, according to the textbook. so I split the equation up into [(4/u)+(u/u)] then I rewrote that to [(4)(1/u) + (u)(1/u)] from that I got 4ln|u| + (1/2)(u^2) ln|u|. What am I still doing wrong?? If...

Homework Statement Find the anti-derivative: \int[(4+u)/u]du The Attempt at a Solution I've tried a couple different ways to find this anti-derivative and I know I keep missing something. I tried to split it up into \int(4+u)(u^-1)du but then I think I do something wrong because I...

Hi, I've got two questions here that I'm stuck on. The first: Homework Equations Find the Limit as x->0 of [(e^4x)-1-4x]/x^2 The Attempt at a Solution So far: I got that the Limit as x->0 is indeterminate form 0/0 so I tried L'Hopital's: to find the Limit as x->0 of [(e^4x)-4]/2x...