Let y1(x) be any non - trivial real valued solution of y"(x) + xy(x) = 0, 0 < x < ∞. Let y2(x) be the solution of y"(x) + y(x) = x2 + 2, y(0) = y'(0) = 0. Then
1
y1(x) has infinitely many zeros.
2
y2(x) has infinitely many zeros.
3
y1(x) has finitely many zeros.
4
y2(x) has finitely many zeros.