Use the symmetry of each quadratic function to find the maximum or minimum points.

Sketch each graph, showing all axis crossing points.

a. y = x² - 5x - 6

b. y = x² - x - 20

c. y = x² + 4x - 21

d. y = x² + 3x - 28

e. y = x² + 4x + 1

f. y = 15 + 2x - x²