1. **State the problem:**
We have the function $g(x) = 6x^2 - 1$.
(a) Find the average rate of change of $g$ from $x = -5$ to $x = 9$.
(b) Find the equation of the secant line passing through the points $(-5, g(-5))$ and $(9, g(9))$.
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2. **Recall the formula for average rate of change:**
The average rate of change of a function $g$ from $x=a$ to $x=b$ is given by
$$\text{Average rate of change} = \frac{g(b) - g(a)}{b - a}$$
3. **Calculate $g(-5)$ and $g(9)$:**
$$g(-5) = 6(-5)^2 - 1 = 6 \times 25 - 1 = 150 - 1 = 149$$
$$g(9) = 6(9)^2 - 1 = 6 \times 81 - 1 = 486 - 1 = 485$$
4. **Calculate the average rate of change:**
$$\frac{g(9) - g(-5)}{9 - (-5)} = \frac{485 - 149}{9 + 5} = \frac{336}{14} = 24$$
This matches the given answer.
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5. **Find the equation of the secant line:**
The secant line passes through $(-5, 149)$ and $(9, 485)$ with slope $m = 24$.
Use point-slope form:
$$y - y_1 = m(x - x_1)$$
Using point $(-5, 149)$:
$$y - 149 = 24(x - (-5)) = 24(x + 5)$$
6. **Simplify to slope-intercept form:**
$$y - 149 = 24x + 120$$
$$y = 24x + 120 + 149$$
$$y = 24x + 269$$
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**Final answers:**
(a) The average rate of change is $24$.
(b) The equation of the secant line is $$y = 24x + 269$$.
Secant Line A847Bf
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