To evaluate $(f + g)(3)$, we first need to find $f(x)$ and $g(x)$ separately, and then add them together.

Given:

• $f(x) = x^2 + 1$
• $g(x) = x - 4$

Now let's evaluate each function at $x = 3$:

1. Evaluate $f(3)$: $f(3) = 3^2 + 1 = 9 + 1 = 10$

2. Evaluate $g(3)$: $g(3) = 3 - 4 = -1$

Now, we can find $(f + g)(3)$:

$(f + g)(3) = f(3) + g(3) = 10 + (-1) = 9$

Final Answer:

$(f + g)(3) = 9$

Would you like further explanation or details? Here are some related questions to deepen understanding:

1. What is $(f - g)(3)$?
2. How do you evaluate $(f \cdot g)(3)$?
3. Can you find $(f/g)(3)$ if $g(3) \neq 0$?
4. What is $(f + g)(x)$ in general form?
5. How do you find the domain of $f(x)$ and $g(x)$?

Tip: When combining functions, always evaluate the individual functions first before performing the operation (addition, subtraction, etc.).