3-Atechnique level
Zeros, roots, factors, x-intercepts — one place, four names
Recognise that all four words point at the same spot on the graph, and read that spot off the calculator instead of factoring by hand.
In this lecture
- 1
Height zero
what f(x) = 0 is asking
- 2
The x-axis
where the graph's height is 0
- 3
Four names
zero, root, solution, x-intercept
- 4
Factors
(x − c) and the sign flip
- 5
Answer what was asked
often the sum, not the zeros
Past questions this covers
103faster with Desmos7about the same0better by hand
Do these first
The problem we'll work on, after the idea
For f(x) = x² − 2x − 8, what is the sum of the solutions of f(x) = 0?