Math Help Forum - View Single Post

ubhik · #4 April 30th, 2008, 02:28 PM

Thanks for that, I understand that bit a lot more now!!!

but I need to apply it the following question, but I can't seem to get it right!!!

$Ay:=\frac{d^2y}{dx^2} - y$

If I try substiting $y = x^m$

then I get

$Ay = m(m-1)x^{m-2}-x^m$

$Ay = (m^2-m)x^{m-2}-x^m$

$Ay = m^2x^{m-2}- mx^{m-2}-x^m$

I am confused because in the previous example, I was able to find the values of m by solving a quadratic equation of m, but this example, I cannot do that... Does that mean I need to substitute something different for $y$ instead of $x^m$ , because I need to get it into such a form that I can find out what the values of m are as this is going to be my kernel for the rest of the problem... I don't really know what to use instead!!! Can you please help!!!

ubhik