1. **Problem 3:** Given the function $h : x \to px - q$ with $h(-3) = -13$ and $h(2) = -3$, find:
(a) The values of $p$ and $q$.
(b) The values of $p$ and $q$ (repetition of (a), so same answer).
(c) The value of $x$ such that $h(x) = x$ (the value of $x$ which maps onto itself).
**Step 1:** Write the given conditions as equations:
$$h(-3) = p(-3) - q = -3p - q = -13$$
$$h(2) = 2p - q = -3$$
**Step 2:** Solve the system of linear equations:
From the two equations:
$$-3p - q = -13$$
$$2p - q = -3$$
Subtract the second from the first to eliminate $q$:
$$(-3p - q) - (2p - q) = -13 - (-3)$$
$$-3p - q - 2p + q = -13 + 3$$
$$-5p = -10$$
$$p = 2$$
**Step 3:** Substitute $p=2$ into one of the equations to find $q$:
$$2p - q = -3 \implies 2(2) - q = -3 \implies 4 - q = -3 \implies q = 7$$
**Answer for (a) and (b):**
$$p = 2, \quad q = 7$$
**Step 4:** Find $x$ such that $h(x) = x$:
$$h(x) = px - q = x$$
Substitute $p=2$ and $q=7$:
$$2x - 7 = x$$
$$2x - x = 7$$
$$x = 7$$
**Answer for (c):**
$$x = 7$$
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2. **Problem 4:** Given functions $f$ and $g$ from an arrow diagram (not provided explicitly), find:
(a) $g(7)$
(b) $g^2(x) = g(g(x))$
(c) $g(f(x))$
(d) $f(g(x))$
Since the explicit functions or mappings are not provided, we cannot compute exact values or expressions. Please provide the functions or mappings for $f$ and $g$ to proceed.
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3. **Problem 5:** Given functions:
$$g : x \to \frac{1}{x - 1}, x \neq 1$$
$$h : x \to 2x + 3$$
Find:
(a) The functions $g(x)$, $h(g(x))$, $g^2(x) = g(g(x))$, and $h^2(x) = h(h(x))$.
(b) Values of $x$ such that $g(h(x)) = h(g(x)) = \frac{31}{8}$.
**Step 1:** Write the given functions:
$$g(x) = \frac{1}{x - 1}$$
$$h(x) = 2x + 3$$
**Step 2:** Find $h(g(x))$:
$$h(g(x)) = h\left(\frac{1}{x - 1}\right) = 2 \cdot \frac{1}{x - 1} + 3 = \frac{2}{x - 1} + 3$$
**Step 3:** Find $g^2(x) = g(g(x))$:
$$g(g(x)) = g\left(\frac{1}{x - 1}\right) = \frac{1}{\frac{1}{x - 1} - 1} = \frac{1}{\frac{1 - (x - 1)}{x - 1}} = \frac{1}{\frac{2 - x}{x - 1}} = \frac{x - 1}{2 - x}$$
**Step 4:** Find $h^2(x) = h(h(x))$:
$$h(h(x)) = h(2x + 3) = 2(2x + 3) + 3 = 4x + 6 + 3 = 4x + 9$$
**Answer for (a):**
$$g(x) = \frac{1}{x - 1}, \quad h(g(x)) = \frac{2}{x - 1} + 3, \quad g^2(x) = \frac{x - 1}{2 - x}, \quad h^2(x) = 4x + 9$$
**Step 5:** Find $x$ such that:
$$g(h(x)) = h(g(x)) = \frac{31}{8}$$
Calculate $g(h(x))$:
$$g(h(x)) = g(2x + 3) = \frac{1}{(2x + 3) - 1} = \frac{1}{2x + 2} = \frac{1}{2(x + 1)}$$
Set equal to $\frac{31}{8}$:
$$\frac{1}{2(x + 1)} = \frac{31}{8} \implies 2(x + 1) = \frac{8}{31} \implies x + 1 = \frac{4}{31} \implies x = \frac{4}{31} - 1 = -\frac{27}{31}$$
Calculate $h(g(x))$:
$$h(g(x)) = \frac{2}{x - 1} + 3 = \frac{31}{8}$$
Solve for $x$:
$$\frac{2}{x - 1} + 3 = \frac{31}{8}$$
$$\frac{2}{x - 1} = \frac{31}{8} - 3 = \frac{31}{8} - \frac{24}{8} = \frac{7}{8}$$
$$2 = \frac{7}{8}(x - 1)$$
$$2 = \frac{7}{8}x - \frac{7}{8}$$
$$\frac{7}{8}x = 2 + \frac{7}{8} = \frac{16}{8} + \frac{7}{8} = \frac{23}{8}$$
$$x = \frac{23}{8} \cdot \frac{8}{7} = \frac{23}{7}$$
**Answer for (b):**
$$x = -\frac{27}{31} \quad \text{for} \quad g(h(x)) = \frac{31}{8}$$
$$x = \frac{23}{7} \quad \text{for} \quad h(g(x)) = \frac{31}{8}$$
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4. **Problem 6:** Given the inverse function:
$$g^{-1}(x) = \frac{x - 4}{11}$$
Find the function $g$.
**Step 1:** Recall that if $g^{-1}(x) = \frac{x - 4}{11}$, then $g$ is the inverse of this function.
Let $y = g^{-1}(x) = \frac{x - 4}{11}$.
To find $g$, solve for $x$ in terms of $y$:
$$y = \frac{x - 4}{11} \implies 11y = x - 4 \implies x = 11y + 4$$
Since $y = g^{-1}(x)$, then $x = g(y)$.
Replace $y$ by $x$ to write $g(x)$:
$$g(x) = 11x + 4$$
**Answer:**
$$g(x) = 11x + 4$$
Function Problems
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