Lesson Plan - Get It!
- We see lines everywhere in math, but what about arches and curves?
- 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!