Question: Worked Examples
1 Graph $y \geq x^2 - 2$
2 Graph $y < x^2 + 2x - 3$
3 Graph $x^2 + y \leq 16$
4 Graph $y > -x^2 + 6$
5 Graph $y \leq x^2 - 4x + 1$
1. **Problem:** Graph the inequality $y \geq x^2 - 2$.
**Step 1:** Identify the boundary curve: $y = x^2 - 2$ is a parabola opening upwards with vertex at $(0,-2)$.
**Step 2:** Since the inequality is $\geq$, shade the region above or on the parabola.
**Step 3:** The parabola is solid because points on it satisfy the inequality.
2. **Problem:** Graph the inequality $y < x^2 + 2x - 3$.
**Step 1:** Boundary curve: $y = x^2 + 2x - 3$ is a parabola opening upwards.
**Step 2:** Rewrite in vertex form: $$y = (x+1)^2 - 4$$ vertex at $(-1,-4)$.
**Step 3:** Since inequality is $<$, shade below the parabola.
**Step 4:** Use a dashed curve because points on the parabola are not included.
3. **Problem:** Graph the inequality $x^2 + y \leq 16$.
**Step 1:** Rewrite as $y \leq 16 - x^2$.
**Step 2:** Boundary curve: $y = 16 - x^2$ is a downward-opening parabola with vertex at $(0,16)$.
**Step 3:** Shade the region below or on the parabola.
**Step 4:** Solid curve because $\leq$ includes boundary.
4. **Problem:** Graph the inequality $y > -x^2 + 6$.
**Step 1:** Boundary curve: $y = -x^2 + 6$ is a downward-opening parabola with vertex at $(0,6)$.
**Step 2:** Since inequality is $>$, shade above the parabola.
**Step 3:** Use a dashed curve because points on the parabola are not included.
5. **Problem:** Graph the inequality $y \leq x^2 - 4x + 1$.
**Step 1:** Rewrite in vertex form:
$$y = (x^2 - 4x + 4) - 3 = (x-2)^2 - 3$$ vertex at $(2,-3)$.
**Step 2:** Since inequality is $\leq$, shade below or on the parabola.
**Step 3:** Use a solid curve because boundary points are included.
**Summary:**
- For $\geq$ or $\leq$, use solid boundary curves and shade above or below accordingly.
- For $>$ or $<$, use dashed boundary curves and shade above or below accordingly.
- Convert quadratic expressions to vertex form to identify vertex and direction.
This completes the solutions for all five graphing inequalities.