1. **State the problem:** Given two functions $f(x) = x^2 + 5x + 6$ and $g(x) = x + 3$, find the following combined functions:
- $(f + g)(x)$
- $(f - g)(x)$
- $(f \cdot g)(x)$
- $\left(\frac{f}{g}\right)(x)$
2. **Recall the formulas:**
- Sum: $(f + g)(x) = f(x) + g(x)$
- Difference: $(f - g)(x) = f(x) - g(x)$
- Product: $(f \cdot g)(x) = f(x) \times g(x)$
- Quotient: $\left(\frac{f}{g}\right)(x) = \frac{f(x)}{g(x)}$, where $g(x) \neq 0$
3. **Calculate each:**
- $(f + g)(x) = (x^2 + 5x + 6) + (x + 3) = x^2 + 5x + 6 + x + 3 = x^2 + 6x + 9$
- $(f - g)(x) = (x^2 + 5x + 6) - (x + 3) = x^2 + 5x + 6 - x - 3 = x^2 + 4x + 3$
- $(f \cdot g)(x) = (x^2 + 5x + 6)(x + 3)$
Multiply each term:
$$x^2 \times x = x^3$$
$$x^2 \times 3 = 3x^2$$
$$5x \times x = 5x^2$$
$$5x \times 3 = 15x$$
$$6 \times x = 6x$$
$$6 \times 3 = 18$$
Sum all:
$$x^3 + 3x^2 + 5x^2 + 15x + 6x + 18 = x^3 + 8x^2 + 21x + 18$$
- $\left(\frac{f}{g}\right)(x) = \frac{x^2 + 5x + 6}{x + 3}$
Factor numerator:
$$x^2 + 5x + 6 = (x + 2)(x + 3)$$
So:
$$\frac{(x + 2)(x + 3)}{x + 3}$$
Cancel common factor $x + 3$ (where $x \neq -3$):
$$\frac{\cancel{(x + 3)}(x + 2)}{\cancel{(x + 3)}} = x + 2$$
4. **Final answers:**
- $(f + g)(x) = x^2 + 6x + 9$
- $(f - g)(x) = x^2 + 4x + 3$
- $(f \cdot g)(x) = x^3 + 8x^2 + 21x + 18$
- $\left(\frac{f}{g}\right)(x) = x + 2$, with $x \neq -3$
These results show how to combine functions by addition, subtraction, multiplication, and division, applying algebraic operations and factoring to simplify expressions.
Function Operations E0C04F
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