If the graph shows shading on or above the line y = 4, which inequality describes the region?

If the graph shows shading on or above the line y = 4, which inequality describes the region?

• A. y > 4
• B. y < 4
• C. y >= 4
• D. y <= 4

Answer: (C)

Shading on or above a horizontal line means every point in the region has a y-coordinate that's at least that line’s value. The line is y = 4, and since the shading includes the line itself, the inequality uses “greater than or equal to.” So the region is described by y ≥ 4. If the shading were strictly above, it would be y > 4; if it were below, it would be y < 4; if it included the line but extended below, it would be y ≤ 4.

Shading on or above a horizontal line means every point in the region has a y-coordinate that's at least that line’s value. The line is y = 4, and since the shading includes the line itself, the inequality uses “greater than or equal to.” So the region is described by y ≥ 4. If the shading were strictly above, it would be y > 4; if it were below, it would be y < 4; if it included the line but extended below, it would be y ≤ 4.