Quadratic Vertices Bad29C
1. **State the problem:** We are given two quadratic functions:
$$y = -2x^2 - 8x - 8$$
$$y = 4x^2 - 8x - 6$$
We need to analyze their shapes, find their vertices, and understand their graph behavior.
2. **Recall the vertex formula:** For a quadratic function in the form $$y = ax^2 + bx + c$$, the vertex \((h, k)\) is found by:
$$h = -\frac{b}{2a}$$
$$k = f(h) = a h^2 + b h + c$$
3. **Analyze the first function:** $$y = -2x^2 - 8x - 8$$
- Here, $$a = -2$$, $$b = -8$$, $$c = -8$$.
- Calculate $$h$$:
$$h = -\frac{-8}{2 \times -2} = -\frac{-8}{-4} = -2$$
- Calculate $$k$$:
$$k = -2(-2)^2 - 8(-2) - 8 = -2(4) + 16 - 8 = -8 + 16 - 8 = 0$$
- So, the vertex is at $$(-2, 0)$$.
- Since $$a = -2 < 0$$, the parabola opens downward.
4. **Analyze the second function:** $$y = 4x^2 - 8x - 6$$
- Here, $$a = 4$$, $$b = -8$$, $$c = -6$$.
- Calculate $$h$$:
$$h = -\frac{-8}{2 \times 4} = \frac{8}{8} = 1$$
- Calculate $$k$$:
$$k = 4(1)^2 - 8(1) - 6 = 4 - 8 - 6 = -10$$
- So, the vertex is at $$(1, -10)$$.
- Since $$a = 4 > 0$$, the parabola opens upward.
5. **Summary:**
- The first parabola opens downward with vertex at $$(-2, 0)$$.
- The second parabola opens upward with vertex at $$(1, -10)$$.
- Both are quadratic functions with standard parabolic shapes.
6. **Graph description:**
- The first parabola peaks at $$(-2, 0)$$ and opens downward.
- The second parabola has its minimum at $$(1, -10)$$ and opens upward.
- These vertices help position the graphs on the coordinate plane, with the first parabola higher and to the left, and the second lower and to the right.