The constant shelling did not bother him as much as the loss of his food. As the siege wore on, fewer and fewer horses, mules, and dogs were seen wandering about Vicksburg. Shoe leather became a last resort of sustenance for many adults.
If the graph of a quadratic function has two x-intercepts, then the line of symmetry is the vertical line through the midpoint of the x-intercepts. The x-intercepts of the graph above are at -5 and 3. The line of symmetry goes through -1, which is the average of -5 and 3. (-5 + 3)/2 = -2/2 = -1.
The graph of a quadratic function is a parabola. A parabola can cross the x-axis once, twice, or never. These points of intersection are called x-intercepts or zeros. In your textbook, a quadratic function is full of x 's and y 's. This article focuses on the practical applications of quadratic functions. In the real world, the x 's and y 's are replaced with real measures of time, distance, and money. To avoid confusion, this article focuses on zeros and not x-intercepts.