Watch Out for Those Curves!

Lesson Plan - Get It!

Audio:

• What happens when information increases and then decreases?
• What about when it decreases and then increases?

Curves are everywhere in math -- we just need to look for them!

A parabola is a U-shaped graph that opens up or down. The equation, which forms a parabola, is called a quadratic function and is in the form y = ax² + bx+ c.

Graphing a parabola can be challenging, but here is a sure-fire way to get it done!

Let's look at the quadratic function y = x² - 2x - 3.

Substitute the x values listed below into this quadratic function to determine the corresponding y values:

Here is what it looks like as we substitute each x into the function. Notice when we substitute the first x, which is -1, we will get 0. So, the first point is (-1,0). Then we repeat for each remaining x.

Now, we need to plot each of those points on the graph. As you see, instead of a line, we have a curve called a parabola!

• What would make the parabola open in the opposite direction?

Let's go to the Got It? section to find out!