How to construct a parabola

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A short video showing how to construct a parabola. The height of each column of coins is its distance from the centre, squared. So 1² = 1. 2² = 4. 3² = 9. And so on.

How to construct a parabola slideshow

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WHAT YOU NEED: 182 coins and card.
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STEP 1: Place a coin on a flat surface. Next to it, place four coins in the shape of a square.
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STEP 2: Repeat this four times, increasing the size of the square by 1 coin in width and height each time. You should be left with 6 squares.
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STEP 3: Stack each square of coins into a pile - you should have 6 piles of coins which increase in size from left to right.
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STEP 4: Repeat this in the opposite direction. The second set of coins should decrease in height from right to left.
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You can see that the coins in this formation make a parabola (a u-shaped symmetrical curve). You can see this clearly if you line the coins up with a piece of card and draw a curve along the edge of the piles of coins.

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Algebra

How to construct a parabola slideshow

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More on Straight line graphs