← Day 22
UNIT 6 / 8 · LESSON 4 / 4 · 22 MINUTES

Use the calculator as a check, not a guess

Graphing can reveal intersections and behavior quickly, but the axes and requested quantity still need interpretation.

01 / THE METHOD

Make it repeatable

  1. Enter the equation or both sides as separate graphs.
  2. Locate intersections or zeros.
  3. Check scale and units.
  4. Substitute the candidate value to verify it solves the original condition.
02 / WORKED EXAMPLE

Watch the method in action

Solve 2x + 3 = 11 with a graphing calculator.
  1. Graph y = 2x + 3 and y = 11.
  2. Read their intersection x-coordinate as 4.
  3. Verify 2(4) + 3 = 11.

The solution is x = 4, not the y-coordinate 11.

03 / QUICK CHECK

Try it yourself

What should you read at the intersection?

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.