Quadratic Analysis 3B2286
1. **State the problem:** We need to analyze the quadratic function $f(x) = x^2 - 6x + 5$ by finding its x-intercepts, y-intercept, vertex, and axis of symmetry.
2. **Formula and rules:**
- The x-intercepts are found by solving $f(x) = 0$.
- The y-intercept is $f(0)$.
- The vertex of a parabola $ax^2 + bx + c$ is at $x = -\frac{b}{2a}$.
- The axis of symmetry is the vertical line through the vertex, $x = -\frac{b}{2a}$.
3. **Find x-intercepts:**
Solve $x^2 - 6x + 5 = 0$.
Use the quadratic formula: $$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$ where $a=1$, $b=-6$, $c=5$.
Calculate discriminant: $$\Delta = (-6)^2 - 4 \times 1 \times 5 = 36 - 20 = 16$$
Calculate roots:
$$x = \frac{6 \pm \sqrt{16}}{2} = \frac{6 \pm 4}{2}$$
So,
$$x_1 = \frac{6 + 4}{2} = 5$$
$$x_2 = \frac{6 - 4}{2} = 1$$
4. **Find y-intercept:**
Evaluate $f(0)$:
$$f(0) = 0^2 - 6 \times 0 + 5 = 5$$
5. **Find vertex:**
Calculate $x$-coordinate:
$$x_v = -\frac{b}{2a} = -\frac{-6}{2 \times 1} = 3$$
Calculate $y$-coordinate:
$$y_v = f(3) = 3^2 - 6 \times 3 + 5 = 9 - 18 + 5 = -4$$
Vertex is at $(3, -4)$.
6. **Axis of symmetry:**
The axis of symmetry is the vertical line through the vertex:
$$x = 3$$
**Final answer:**
- x-intercepts: $(1, 0)$ and $(5, 0)$
- y-intercept: $(0, 5)$
- vertex: $(3, -4)$
- axis of symmetry: $x = 3$