Across
1
Number less than zero
4
Reference line in a graph
6
Rectangular array of numbers
7
U-shaped curve of a quadratic function
8
Sum divided by count
Down
2
Difference between highest and lowest values
3
Exact correspondence on both sides
5
Steepness of a line
9
Distance from center to edge of circle
10
Mathematical statement of equality
11
The number representing nothing