1. **State the problem:** We have a quadratic function $g(x) = ax^2 + q$ with x-intercepts $R$ and $S(2,0)$, and y-intercept $T(0,8)$. A linear function $f(x) = mx + c$ passes through points $R$ and $T$. We need to find the equations of $g$ and $f$.
2. **Find $q$ using the y-intercept of $g$:** Since $T(0,8)$ lies on $g$, substitute $x=0$:
$$g(0) = a(0)^2 + q = q = 8$$
So, $q = 8$.
3. **Use the x-intercept $S(2,0)$ on $g$:** Substitute $x=2$, $g(2) = 0$:
$$0 = a(2)^2 + 8 = 4a + 8$$
Solve for $a$:
$$4a = -8 \Rightarrow a = -2$$
4. **Find the other x-intercept $R$ of $g$:** The quadratic is
$$g(x) = -2x^2 + 8$$
Set $g(x) = 0$ to find x-intercepts:
$$-2x^2 + 8 = 0 \Rightarrow -2x^2 = -8 \Rightarrow x^2 = 4 \Rightarrow x = \pm 2$$
We already have $S(2,0)$, so $R$ is at $(-2,0)$.
5. **Find the equation of $f(x) = mx + c$ passing through $R(-2,0)$ and $T(0,8)$:**
Calculate slope $m$:
$$m = \frac{8 - 0}{0 - (-2)} = \frac{8}{2} = 4$$
Use point-slope form with point $T(0,8)$:
$$y - 8 = 4(x - 0) \Rightarrow y = 4x + 8$$
**Final answers:**
$$g(x) = -2x^2 + 8$$
$$f(x) = 4x + 8$$
Quadratic Linear
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