1. **State the problem:** Given functions $f(x) = x^3 - 2$ and $g(x) = \frac{5x + 3}{1 - 2x}$, find the composition $(g \circ f)(x)$ and the inverse function $g^{-1}(x)$.
2. **Find $(g \circ f)(x)$:** This means $g(f(x))$.
Substitute $f(x)$ into $g$:
$$g(f(x)) = \frac{5(f(x)) + 3}{1 - 2(f(x))} = \frac{5(x^3 - 2) + 3}{1 - 2(x^3 - 2)}$$
3. **Simplify numerator and denominator:**
Numerator:
$$5(x^3 - 2) + 3 = 5x^3 - 10 + 3 = 5x^3 - 7$$
Denominator:
$$1 - 2(x^3 - 2) = 1 - 2x^3 + 4 = 5 - 2x^3$$
So,
$$g(f(x)) = \frac{5x^3 - 7}{5 - 2x^3}$$
4. **Find $g^{-1}(x)$:** To find the inverse, start with
$$y = \frac{5x + 3}{1 - 2x}$$
Swap $x$ and $y$:
$$x = \frac{5y + 3}{1 - 2y}$$
5. **Solve for $y$:** Multiply both sides by denominator:
$$x(1 - 2y) = 5y + 3$$
Distribute:
$$x - 2xy = 5y + 3$$
Group $y$ terms on one side:
$$-2xy - 5y = 3 - x$$
Factor out $y$:
$$y(-2x - 5) = 3 - x$$
6. **Divide both sides by $-2x - 5$:**
$$y = \frac{3 - x}{-2x - 5}$$
Rewrite denominator:
$$y = \frac{3 - x}{-(2x + 5)} = -\frac{3 - x}{2x + 5} = \frac{x - 3}{2x + 5}$$
7. **Final answers:**
$$(g \circ f)(x) = \frac{5x^3 - 7}{5 - 2x^3}$$
$$g^{-1}(x) = \frac{x - 3}{2x + 5}$$
Function Composition Inverse 9C79E1
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