Answer to Question #243685 in Differential Equations for Mohammed

Question

4 d²y/dx²+25y=0

Answer 1

Characteristic equation: $4r^2+25=0$

$r=\frac{5}{2} i, i=-\frac{5}{2}i$.

General solution of DE: $y=C_1sin(\frac{5}{2}x)+C_2cos(\frac{5}{2}x)$.