Algebra 2A — Functions & Quadratics
Part 1 of 2. Functions as machines (and composition), the quadratic formula & discriminant, and the parabola's vertex.
Lines were straight; now they bend. Algebra 2 is about curves — and the idea that ties them together: the function. This is part 1 of 2.
- 01 Functions — machines with one output ELI5: a function is a machine: drop an input in, get exactly one output. Write f(x) = 2x + 1 and "f(3)" means "run 3 through the machine" →…
- 02 Quadratics & the discriminant ELI5: a quadratic ax² + bx + c = 0 graphs as a parabola (a U or ∩). Its entire personality hides in one number, the discriminant b² − 4ac: positive → two real…
- 03 The vertex — a parabola's turning point ELI5: every parabola has a single lowest (or highest) point, the vertex, sitting at x = −b/2a — exactly halfway between the two roots. For y = x² − 6x + 5…
next course: Algebra 2B — Exponentials, Logs & Sequences →