The video tutorial introduces the concept of functions, explaining the relationship between input and output values. It covers how functions are named using variables and demonstrates evaluating functions F, G, and H at specific inputs. The tutorial emphasizes the importance of using parentheses to avoid errors when dealing with negative numbers.

What is the main characteristic of a function in terms of input and output?

• Outputs are always greater than inputs.

• Inputs and outputs are interchangeable.

• Every output is unique to its input.

• Every input has multiple outputs.

In the function F(x) = 3x + 2, what is the output when the input is -5?

• 15

• 13

• -13

• -15

Why is it important to use parentheses when substituting values into functions?

• To avoid errors with negative numbers.

• To ensure correct order of operations.

• To simplify the function.

• To make the equation look neat.

What is the result of G(-3) if G(x) = -2x^2?

• 9

• -9

• 18

• -18

For the function H(x) = -4x^2 - 2x + 5, what is H(2)?

• -15

• 15

• -20

• 20