Find all functions f:R
+->R satisfying:
f(1)=1,
f has second derivative and
f'(1/x)=-(1/2)f(x).
This works except for a sign change:
f(x) = c x^(1/2)
f'(x) = (c/2) x^(-1/2)
f'(1/x) = (c/2) x^(-1/2) = (1/2) f(x), but not -(1/2) f(x)
Edited on January 23, 2024, 8:58 am