Recent content by shorty1

Let f(x,y) = (x-y)/(x+y). find the directions u and the values of $D_{u}f $ (-1/2 , 3/2) for which $D_{u}f $ (-1/2 , 3/2) is largest, and is smallest. How do i go about that? I did it for when $D_{u}f $ (-1/2 , 3/2) = 1 and got $D_{u}f $ (-1/2 , 3/2) = 1 and got u=j and -i. This was after i...

This was the easy part. I got that far but when I did my substitution for the coefficients into the equation my particular solution wasn't adding up.. :(

Thank you, but I got that far into the separation, but I wasn't sure how to proceed from there, my integrals kept repeating when I tried it by parts, and I wasn't getting anything to substitute to use that wasn't still leaving me with multiple variables to integrate. ...

Something i am doing is not adding up. I don't understand the part with the external force. here's the question: Show that the solution for the damped free forced vibration given by is when , where something along the way I'm doing wrong, because not for heck can i get that fraction with...

I have a question that has stumped me a bit, i am not sure how to use the definition to calculate it, i can use the tables, but i don't think that's what is needed. Using the definition of the Laplace transform, determine the Laplace transform of I can do it with the table but i am not sure...

Thank you, one more thing: what do you do with the constant of integration when forming the general solution? I have $$ y = C_1 e^{2x} c_2 e^{-x} $$ as my general solution. what should i have done with the Constant of integration?

I semi understand the reduction of order method, and i understand the general solution for a 2nd order with repeated roots. however, i can't seem to form up the correct thing to solve this question, and research again proves futile. Any assistance will be appreciated. Use the method of...

Oh, thanks, i was using the font options enclosed in the text box. just where you choose the font and other options above where you type. there are sub and superscript tabs. thanks, i will not use those in future. ---------- Post added at 06:29 ---------- Previous post was at 06:29...

thanks, but this is not what i need, i got this part already myself. my problem is the part after.. i don't kno how to calculate this with the info given.. all the examples i have seen don't show how to do it.. the coefficients are not constant, so the auxiliary equation doesn't work.. i don't...

neither. i tried that too. is it me? i just restarted my browser and getting the same thing. the thing is when i started writing the question i previewed just as i started and the math came out fine, then when i added more it messed up and that was it.

well your 'iput' came out as Math. same thing was happening to part of what i was writing, and not the actual math that i wanted in the latex.

isn't that what I've done?

I was given a question and i am really unsure how to go about solving it. it appears to be solveable using the characteristic equation and whatnot, however i have my coeffecients in terms of the independent variable. so i am confused. the question initially asked to compute the wronskian, and it...

yes. but how am i using the z substitution to show anything..?

Thanks, But how does that tie into the 1st part which says to show the substitutions z=ax + by + c changes y' = f(ax + by + c) into an equation with separable variables...??