So far, you've learned that the value of h tells us how far a function has moved left or right. The value of k tells us where the vertex is located on the y-axis. This value also tells us how far up or down the function has moved from the vertex (0,0) of the parent function. Let's start with the parent function shown here.

If k is positive, the function moves k units up. Take a look at the graph of f(x) = x\(\small\mathsf{ ^2 }\) + 3.

If k is negative, the function moves k units down. Take a look at the graph of f(x) = x\(\small\mathsf{ ^2 }\) - 3.

The k values gives us information about the vertical shift of the function, also called the vertical translation.

• If k is positive, the graph will move up k units.
• If k is negative, the graph will move down k units.