dsolve function returning empty sum

Following is the code to solve ode 2nd order ODE d^2y/dt^2+y=0; y(0)=1; y'(0)=0;

I find that the following code works

dsolve('D2y+y=0','y(0)=1','Dy(0)=0')

and it does not work when following code is executed(very equivalent of above code), returns empty sum

syms y(t)
 eqn= diff(y,t,2)+ y ==0;
dsolve(eqn,'y(0)=1','Dy(0)=0')

Any idea, sure I did not understand something.

[madhan ravi]

which version of matlab are you using?

[Raghuraman S]

Hi 2018b

Answer 1

[Walter Roberson]

syms y(t)
dy = diff(y,t);
eqn = diff(y, t, 2) + y == 0;
dsolve(eqn, y(0)==1, dy(0)==0)

[Raghuraman S]

Thank you , it works.