# Search results

1. ### Solve y''+9y=delta(t-pi)

Solve the differential equation y''+9y=delta(t-pi) that fulfills the initial condition y(0)=y(0)=1. Answer by giving the value for y((14*pi)/9). The answer can be given by a fraction a/b. The Attempt at a Solution I will submit my attempt for a solution as an attachment shortly.
2. ### Diffusion Problem (Conduction)

Homework Statement Since the problem involved formulas I have posted it as an attachment. Please check the attachment first. (I have not scanned this problem, just wrote it in word and posted it) The Attempt at a Solution My approach on this problem is to start with separation of variables...
3. ### Fourierseries of X^2-1

Determine the fourierseries of the function f(x)=x^2−1 defined on the interval [-pi,pi]. What will the coefficient a/b be in front of the cos3x in the fourierseries? I am not sure how to start this solving this problem. Pls help.
4. ### Three Critical Points and Type of Local Phaseportrait

Homework Statement y1'= −4*y1+y2+y1*y2 y2'= −2*y1−y2+y1*y1 Determine the three critical points of the system and their type of local phase portrait (stable node, unstable, saddle point, spiral, center, no node) Hence I need to get three critical points (x1,y1), (x2,y2) & (x3,y3) and their...
5. ### System of Differential Equations

SOLVE THE SYSTEM OF DIFFERENTIAL EQUATIONS: X'= -x+y Y'= -x-y WHEN x(0)=2 och y(0)=3. The Attempt at a Solution HELP...I don't know how to go about this. I have used the matrix A= [-1 1 -1 -1] and got a lambda1=-1+i lambda2=-1-i and eigenvectors: [1...