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**Vamz** $\displaystyle y^{\prime \prime} + 25 y = 0$

Initial Conditions are:

$\displaystyle y(0)=-1,\quad y(\frac{\pi}{10})=-2$

So, My roots are $\displaystyle 0\pm10i$

Its in the form P+- qi

Does the fact that my P=0 change anything? Or should I just roll with it?

Anyways, heres what I did

$\displaystyle Y=ACos(5x)+Bsin(5x))$

$\displaystyle Y'=-A5sin(5x)+B5Cos(5x)$

So, when Y(0)=-1

We get $\displaystyle A=-1$

When $\displaystyle Y'(\frac{\pi}{10})=-2$

we get:

$\displaystyle -2=-A5$ which is just a false statement.

Im not able to isolate "B" given the initial conditions. What am I doing wrong?