Recent content by Pete69

if you look at my other topic (a few below this one in this section, about free fall under gravity) you will see where it came from... iv only just come across linear constant coefficient second order DEs (homogenous and non-homogenous) so now know how to solve the x'' + ax = 0 part... but my...

Homework Statement I was given a problem to solve for the speed of a body falling under gravity [equation (1)] where g is acceleration due to gravity, which was easy enough.. but then i thought i would extend it to the case where g is non-constant, and so arrived at equation (2), (where where...

ive followed the link, and have come to a solution of y = A + B*exp(-ax) (1) for y'' + ay' = 0 but then using the D and then Q operators i run into problems when trying to find the particleur integral of y'' + ay' = -by^n due to the A term in equation (1), which i cannot use the...

wel the only second order DE i have experience of solving are linear constant coefficient ones, and this doesn't look like any I've come across before.. so i jst assumed this was non-linear... thanks for the link and help, i think i get it now..

wait... i don't kno how to solve x'' + ax' = 0 haha

aah yes coz the sums of the solutions is a solution or summit like tht right?? cheers

well substituing u=x' i get the equation u' + au = -bx^n which is of the form y' +ay = f(x) and so I multiply by the relevant integrating factor to solve, but the algebra gets very hard.. i only know how to solve linear second order DE, and got the idea of substituting x'=u from other...

could anyone help me with solving this second order differential equation? I am a noob on here so not sure how you get the mathplayer stuff on... so the equation is of the form x'' +ax' + bx^n = 0 (x^n means x to the power n, with a and b constants). i tried substituting x'=u to get a first...