← Day 16
UNIT 6 / 8 · LESSON 2 / 4 · 27 MINUTES

Read the useful form of a quadratic

Factored form reveals zeros; vertex form reveals a maximum or minimum; standard form helps expand and compare.

01 / THE METHOD

Make it repeatable

  1. Look at the question first: zeros, vertex, or a value?
  2. Choose the form that exposes that feature.
  3. Factor or complete the square only when needed.
  4. Check a value by substitution or graph.
02 / WORKED EXAMPLE

Watch the method in action

For y = (x − 2)(x + 5), find the x-intercepts.
  1. At an intercept, y = 0.
  2. Set each factor to zero.
  3. x = 2 or x = −5.

The graph crosses the x-axis at 2 and −5.

03 / QUICK CHECK

Try it yourself

Which pair gives the zeros?

04 / PRACTISE AND CHECK

Apply the method to real questions

Start with guided questions and feedback. Then take a fresh independent set without hints. Reach at least 80% on that set to record this lesson.

Pass the quick check above to unlock practice.