If , integrate once to get , integrate again to get .
the indicated y1 is a solution of the given differential equation. find a second solution y2(x).
so my problem is: y'' -4y' + 4y = 0 , y1 = e^(2x)
if y=u(x)y1(x) then y= u(x)e^(2x).
after finding y'' and y' i substituted back into the original equation and got,
u''e^(2x) = 0. and this is where i am stuck. I am not sure what to do.
i know that u'' must be 0.
my book goes on to say that, u= c1x + c2? and that c1= 1 and c2=0 and that
a little help please....
thanks in advance.