Thread: undetermined coefficients

was just wondering how i'd go about using the method of undetermined coefficients to find a particular solution of
y"=a

the only solution i've come up with seems too simple.
any help is greatly appreciated!

Originally Posted by feronius

was just wondering how i'd go about using the method of undetermined coefficients to find a particular solution of
y"=a

the only solution i've come up with seems too simple.
any help is greatly appreciated!

i donot know what are undetermined coefficients. but the solution to your equation will be ax^2/2+c1.x+c2 where c1 and c2 are "undetermined coefficients"(saying literally) which you can find out if some initial value is given.

Originally Posted by feronius

was just wondering how i'd go about using the method of undetermined coefficients to find a particular solution of
y"=a

the only solution i've come up with seems too simple.
any help is greatly appreciated!

This is actually a simple problem.

The Fundamental solutions are Y(t)=x+yt, where x,y is constant
so let the particular solution has the form of .
Then, Y"=2A, then sub it back to the equation and you will get 2A=a.
so A =a/2.

Hope this helps