144 Part 2: Into the Unknown
CHECK POINT
Graph each equation using y-intercept and slope.- yx^3
4
5 -^11 - yx 51 - 46
23. yx 5 - 342
24. 256 yx
25. yx63 1
Vertical and Horizontal Lines
Horizontal lines fit the y = mx + b pattern, but since they have a slope of zero, they become y = 0.
Whatever value you may choose for x, the y-coordinate will be b.
Vertical lines have undefined slopes, so they cannot fit the y = mx + b pattern, but since every
point on a vertical line has the same x-coordinate, they can be represented by an equation of the
form x = c, where c is a constant. The value of c is the x-intercept of the line.CHECK POINT
Graph each equation.- y = -3
- x = 2
- y = 5
29. x = -1
30. y + 1 = 4