Skip to main content

The U-Shaped Curve of Squaring

When you square every input, the results never drop below zero, so the graph falls to a lowest point and then climbs back up. Opposite inputs like -3 and 3 give the same output, which is why the two sides look like mirror images.

In the picture

  1. The ink dot at the bottom of the curve, its lowest point.
  2. The dashed vertical line running through that lowest point.
  3. The red cross marked on the left arm of the curve.
  4. The matching red cross on the right arm, at the same height.

Examples

  • The cable of a suspension bridge sags to one low point and rises the same way toward each tower.
  • A satellite dish cut down the middle shows the same rounded shape on both halves.

Quiz: The U-Shaped Curve of Squaring (Age 15)

  1. When you square every input, what is the smallest output you can ever get?

    • Zero
    • A small negative number
    • There is no smallest output
  2. Squaring 4 gives 16. Which other input also gives 16?

    • -4
    • -16
    • 8
  3. If you could fold the graph of the square function so that the two halves matched exactly, where would the fold line have to run?

    • A vertical line through the lowest point
    • A horizontal line through the lowest point
    • A diagonal line through the lowest point

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.

Get the app

Free app, optional subscription
App Store Google Play

Carry on in the app

At least one new illustrated lesson every weekday for your child’s year, with its quiz and a reminder at 6:15 pm.

Your child’s teacher does not use My Enhanced Teacher yet?

Tell them about it

Maths, Age 15