1. **State the problem:** We are given two functions $f(x) = 3x - 4$ and $g(x) = 4x + 1$. We need to find:
(a) $f(-2)$
(b) The inverse function $f^{-1}(x)$
(c) The composition $fg(x)$ and find constants $a$ and $b$ such that $fg(x) = ax + b$
2. **Find $f(-2)$:**
Substitute $x = -2$ into $f(x)$:
$$f(-2) = 3(-2) - 4 = -6 - 4 = -10$$
3. **Find the inverse function $f^{-1}(x)$:**
The inverse function reverses the roles of $x$ and $y$. Start with:
$$y = 3x - 4$$
Swap $x$ and $y$:
$$x = 3y - 4$$
Solve for $y$:
$$3y = x + 4$$
$$y = \frac{x + 4}{3}$$
So,
$$f^{-1}(x) = \frac{x + 4}{3}$$
4. **Find $fg(x)$:**
The composition $fg(x)$ means $f(g(x))$.
Substitute $g(x)$ into $f$:
$$fg(x) = f(g(x)) = f(4x + 1) = 3(4x + 1) - 4$$
Simplify:
$$= 12x + 3 - 4 = 12x - 1$$
5. **Identify $a$ and $b$:**
From $fg(x) = ax + b$, we have:
$$a = 12, \quad b = -1$$
**Final answers:**
(a) $f(-2) = -10$
(b) $f^{-1}(x) = \frac{x + 4}{3}$
(c) $a = 12$, $b = -1$
Function Evaluation 649300
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