Answer:
0.75.
Explanation:
1) the required vertical distance is the distance between two vertexes.
2) according to the item 1, the coordinates of the vertexes are:
(y=x²+1): x₀=0; y₀=1;
(y=x-x²): x₀=0.5; y₀=0.25;
3) according to the item 2, the distance between 1 and 0.25 is 0.75.