ODE
\[ y''(x)+y(x)=0 \] ODE Classification
[[_2nd_order, _missing_x]]
Book solution method
TO DO
Mathematica ✓
cpu = 0.0210058 (sec), leaf count = 16
\[\left \{\left \{y(x)\to c_2 \sin (x)+c_1 \cos (x)\right \}\right \}\]
Maple ✓
cpu = 0.003 (sec), leaf count = 13
\[ \left \{ y \left ( x \right ) ={\it \_C1}\,\sin \left ( x \right ) +{\it \_C2}\,\cos \left ( x \right ) \right \} \] Mathematica raw input
DSolve[y[x] + y''[x] == 0,y[x],x]
Mathematica raw output
{{y[x] -> C[1]*Cos[x] + C[2]*Sin[x]}}
Maple raw input
dsolve(diff(diff(y(x),x),x)+y(x) = 0, y(x),'implicit')
Maple raw output
y(x) = _C1*sin(x)+_C2*cos(x)