Answer:
Step-by-step explanation:
y=-1/2(x+10)^2+14
2y=-(x+10)^2+28
(x+10)^2=28-2y
L.H.S. is positive.
so 28-2y≥0
28≥2y
or 2y≤28
or y≤ 14
Range is (-∞,14]
