how to solve simple differential equations

Hi all,

How can I solve this equation?!

dx/dt+y=0
dy/dt-x=0
x(0)=3/2
y(0)=0

Thanks

Answer 1

[Star Strider]

This way, if you have the Symbolic Math Toolbox:

syms x(t) y(t)

[x,y] = dsolve(diff(x) + y == 0,  diff(y) - x == 0, x(0)==3/2,  y(0)==0)

x =

(3*cos(t))/2

y =

(3*sin(t))/2