Forgetting the negative sign. The formula is x = -b/(2a), not x = b/(2a). That little negative is like the “no” in “no way, that’s wrong.” Don’t lose it.
Mixing up a and b. Remember: “a” is the squared term’s number, “b” is the linear term’s number, and “c” is just there to look pretty. If you swap a and b, you’ll get a line that goes to the moon—literally wrong.
Axis Of Symmetry
Thinking the axis is a point. Nope. It’s a vertical line, which means you always write it as “x = [some number].” Not (x, y). Not a dot. A line. Like a scar on the graph—but a beautiful one.
