# Second order homogeneous equation

• Sep 30th 2008, 01:53 AM
McCoy
Second order homogeneous equation
I need help here guys. I did it but got the value of B wrong and it seem i cann't get it right.
Given that the general solution of the differential equation

y **- 30 y *+ 225 y = 0 ,

is
y =A x exp(15)x + B exp(15x).

By finding the values of A and B obtain the solution of the initial value problem
y **- 15 y *+ 225 y = 0, y(0) = 9 , y *(0) = 5.

** means second derivative, and * mean first derivative...I couldn't use the keyboard for the appropriates notations.

A = , B = .
• Sep 30th 2008, 02:08 AM
mr fantastic
Quote:

Originally Posted by McCoy
I need help here guys. I did it but got the value of B wrong and it seem i cann't get it right.
Given that the general solution of the differential equation

y **- 30 y *+ 225 y = 0 ,

is
y =A x exp(15)x + B exp(15x).

By finding the values of A and B obtain the solution of the initial value problem
y **- 15 y *+ 225 y = 0, y(0) = 9 , y *(0) = 5.

** means second derivative, and * mean first derivative...I couldn't use the keyboard for the appropriates notations.

A = , B = .

Show the working you did. Any errors can then be pointed out.