1. **Problem Statement:** We are given a parabola that opens upward with vertex near $(-1, -9)$ and need to find:
(a) Whether it opens upward or downward.
(b) The equation of the axis of symmetry.
(c) The coordinates of the vertex.
(d) The x- and y-intercepts.
2. **Key Formulas and Rules:**
- A parabola in vertex form is given by $$y = a(x - h)^2 + k$$ where $(h, k)$ is the vertex.
- The axis of symmetry is the vertical line $$x = h$$.
- The vertex is the point $(h, k)$.
- The x-intercepts are found by solving $$y=0$$.
- The y-intercept is found by evaluating $$y$$ at $$x=0$$.
3. **Given Information:**
- Vertex: $(-1, -9)$ so $h = -1$, $k = -9$.
- Parabola opens upward, so $a > 0$.
4. **Find the equation of the parabola:**
Since the vertex is $(-1, -9)$ and it opens upward, assume $a=1$ for simplicity:
$$y = (x + 1)^2 - 9$$
5. **(a) Direction of opening:**
Since $a=1 > 0$, the parabola opens **upward**.
6. **(b) Axis of symmetry:**
The axis of symmetry is the vertical line through the vertex:
$$x = -1$$
7. **(c) Vertex coordinates:**
The vertex is:
$$(-1, -9)$$
8. **(d) Find intercepts:**
- **x-intercepts:** Set $y=0$:
$$0 = (x + 1)^2 - 9$$
$$ (x + 1)^2 = 9$$
$$x + 1 = \\pm 3$$
So,
$$x = -1 + 3 = 2$$
$$x = -1 - 3 = -4$$
- **y-intercept:** Set $x=0$:
$$y = (0 + 1)^2 - 9 = 1 - 9 = -8$$
**Summary:**
- (a) Upward
- (b) Axis of symmetry: $x = -1$
- (c) Vertex: $(-1, -9)$
- (d) x-intercepts: $2, -4$
- (d) y-intercept: $-8$
Parabola Properties 27F15D
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.