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Level 1 · Geometry · Unit 4 of 4

Two mirrors make a turn

about 7 min · Free · No sign-in needed

Mirror the arrow across one line, then across a second line. The result is no longer a mirror flip: it is a rotation, by twice the angle between the two lines. This is the idea behind Grover's search algorithm, which you will meet by name in level 15.

  1. 1. Predict
  2. 2. Run
  3. 3. Rules
  4. 4. Redraw
  5. 5. Explain
  6. 6. Done

Prediction 1 of 2

Simulated

Predict first, then run it.

|0⟩|1⟩−|0⟩−|1⟩A (Z)B (X)
0° · Z
45° · X

Arrow angle: ? · Pairs applied: 0

The arrow is at 30°. Mirror it across the 0° line (Z), then across the 45° line (X). Where does it end up?

Clears this unit's progress and drawing record on this device.