Final answer:
The statement that is true is option c. f(x) is even and g(x) is odd.
Step-by-step explanation:
The statement that is true is option c. f(x) is even and g(x) is odd.
An even function is one that satisfies the condition f(-x) = f(x), which means that if you replace x with -x in the function, the function remains the same. For f(x) = x² + 3, we have f(-x) = (-x)² + 3 = x² + 3 = f(x), so f(x) is even.
An odd function is one that satisfies the condition f(-x) = -f(x), which means that if you replace x with -x in the function, the function is negated. For g(x) = x² + x + 3, we have g(-x) = (-x)² + (-x) + 3 = x² - x + 3 = -g(x), so g(x) is odd.