7. Which of the following is true? 1. For a pair of functions to be inverses, their compositions must be equal to 1.

2. In an inverse relation, coordinates of the ordered pairs are multiplied by 2.

3. An inverse of a function is always a function.

4. The horizontal line test is used to determine if a function's inverse will be a function.

The horizontal line test is used to determine if a functions inverse will be a function. You will compose the functions (that is, plug x into one function, plug that function into the inverse function, and then simplify) and verify that you end up with just "x". Here's what it looks like: Determine algebraically whether f (x) = 3x – 2 and g(x) = (x + 2)/3 are inverses of each other.

Use the horizontal line test to determine if a function is a one-to-one function.

If ANY horizontal line intersects your original function in ONLY ONE location, your function will be a one-to-one function and its inverse will also be a function.

hope this helps