## Solving an ODE using Galerkin's method

1. The problem statement, all variables and given/known data
Given the ODE $$\frac{df}{dt}=f$$ and the boundary condition $$f(0)=1$$

One approximate solution is $$f_{a}=1+\sum ^{3}_{k=1} a_{k}t^k$$ where $$0\leq t\leq1$$

Using the Galerkin's method find the coeficents $$a_{k}$$
2. Relevant equations

3. The attempt at a solution
I don't think I've understood how to use the method really. So if someone could explain it briefly. Another thing that is mentioned in the book is that the basis funktions are not orthogonal on this interval. So that can not be imposed

Thanks
/Simon

 PhysOrg.com science news on PhysOrg.com >> Hong Kong launches first electric taxis>> Morocco to harness the wind in energy hunt>> Galaxy's Ring of Fire
 You can take the derivative of the general (approximate) solution and plug in the equation. Then equate the terms with the same power of t and you'll get 3 simple equations that will give you the three coefficients a1, a2, a3.