Recent content by nados29

Hi, I need some help in finding whether this differential equation is homogeneous or not. 3 (d^2 y / dx^2) + x (dy/dx)^2 = y^2 I know that for example, x^2 dx + xy dy = 0 is homogeneous. But how can I deal with the equation that has (d^2 y / dx^2) and (dy/dx)^2 ? Thanks

Hi, I have a problem that I can't solve. Please help me. Here is it: ------------------------------------------------------------------------- Verify that the function y = -(cos x) ln (sec x + tan x) is an explicit solution of the differential equation y'' + y = tan x. Assume an...

Thanks a lot :smile: I never thought it can be that simple. Thanks again, Nadine

Hi, I've a riddle that I can't solve. I hope someone can help me in it. Here is it: If we have a number and add the digits of that number, then subtract the summation we got from the original number, why is the result always multiples of the base system minus 1. Here is an example...