Answer:
-25
Step-by-step explanation:
(1) y = -2x²
(2) y = 2x² + k Subtract (1) from (2)
0 = 4x² + k Subtract 4x² from each side
k = -4x²
The parabolas are <em>symmetrical about the y-axis.</em>
Segment AB = 5, so x = +2.5 and x = +2.5.
k = -4(±2.5)² = -4 × 6.25 = -25
