1. **Problem (a):** Sketch the linear function $y = 2x + 3$ and find its slope and y-intercept.
2. The general form of a linear function is $y = mx + b$, where $m$ is the slope and $b$ is the y-intercept.
3. For $y = 2x + 3$, the slope $m = 2$ and the y-intercept $b = 3$.
4. The slope $2$ means the line rises 2 units vertically for every 1 unit it moves horizontally.
5. The y-intercept $3$ means the line crosses the y-axis at the point $(0,3)$.
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1. **Problem (b):** Sketch the quadratic function $y = -x^2 + 4x - 3$ and identify the vertex, axis of symmetry, and intercepts.
2. The quadratic function is in the form $y = ax^2 + bx + c$ with $a = -1$, $b = 4$, and $c = -3$.
3. The vertex formula is $x = -\frac{b}{2a} = -\frac{4}{2(-1)} = 2$.
4. Substitute $x=2$ into the function to find the vertex's y-coordinate:
$$y = -(2)^2 + 4(2) - 3 = -4 + 8 - 3 = 1$$
So, the vertex is at $(2,1)$.
5. The axis of symmetry is the vertical line $x = 2$.
6. To find the y-intercept, set $x=0$:
$$y = -0 + 0 - 3 = -3$$
So, the y-intercept is $(0,-3)$.
7. To find the x-intercepts, solve $-x^2 + 4x - 3 = 0$:
Multiply both sides by $-1$:
$$x^2 - 4x + 3 = 0$$
Factor:
$$(x - 3)(x - 1) = 0$$
So, $x = 1$ or $x = 3$.
The x-intercepts are $(1,0)$ and $(3,0)$.
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1. **Problem (c):** Solve graphically the system:
$$y = x^2 - 3x + 2$$
and
$$y = 2x - 1$$
2. To find the intersection points, set the two expressions equal:
$$x^2 - 3x + 2 = 2x - 1$$
3. Rearrange to form a quadratic equation:
$$x^2 - 3x + 2 - 2x + 1 = 0$$
$$x^2 - 5x + 3 = 0$$
4. Use the quadratic formula:
$$x = \frac{5 \pm \sqrt{(-5)^2 - 4(1)(3)}}{2(1)} = \frac{5 \pm \sqrt{25 - 12}}{2} = \frac{5 \pm \sqrt{13}}{2}$$
5. Approximate the roots:
$$x_1 \approx \frac{5 + 3.606}{2} = 4.303$$
$$x_2 \approx \frac{5 - 3.606}{2} = 0.697$$
6. Find corresponding y-values using $y = 2x - 1$:
$$y_1 = 2(4.303) - 1 = 7.606$$
$$y_2 = 2(0.697) - 1 = 0.394$$
7. The solutions (intersection points) are approximately $(4.303, 7.606)$ and $(0.697, 0.394)$.
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**Final answers:**
- (a) Slope = 2, y-intercept = 3
- (b) Vertex = $(2,1)$, axis of symmetry $x=2$, x-intercepts $(1,0)$ and $(3,0)$, y-intercept $(0,-3)$
- (c) Intersection points approximately $(4.303, 7.606)$ and $(0.697, 0.394)$
Linear Quadratic 7Ed72E
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