Limits of sequences

  • Zooming in on the Squares
    article

    Zooming in on the squares

    Start with a large square, join the midpoints of its sides, you'll see four right angled triangles. Remove these triangles, a second square is left. Repeat the operation. What happens?
  • Continued Fractions I
    article

    Continued fractions I

    An article introducing continued fractions with some simple puzzles for the reader.

  • Continued Fractions II
    article

    Continued fractions II

    In this article we show that every whole number can be written as a continued fraction of the form k/(1+k/(1+k/...)).

  • Infinite Continued Fractions
    article

    Infinite continued fractions

    In this article we are going to look at infinite continued fractions - continued fractions that do not terminate.
  • Small Steps
    problem

    Small steps

    Age
    16 to 18
    Challenge level
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    Two problems about infinite processes where smaller and smaller steps are taken and you have to discover what happens in the limit.
  • Ruler
    problem

    Ruler

    Age
    16 to 18
    Challenge level
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    The interval 0 - 1 is marked into halves, quarters, eighths ... etc. Vertical lines are drawn at these points, heights depending on positions. What happens as this process goes on indefinitely?
  • Slide
    problem

    Slide

    Age
    16 to 18
    Challenge level
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    This function involves absolute values. To find the slope on the slide use different equations to define the function in different parts of its domain.
  • Little and Large
    problem

    Little and large

    Age
    16 to 18
    Challenge level
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    A point moves around inside a rectangle. What are the least and the greatest values of the sum of the squares of the distances from the vertices?
  • Approximating Pi
    problem

    Approximating pi

    Age
    14 to 18
    Challenge level
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    By inscribing a circle in a square and then a square in a circle find an approximation to pi. By using a hexagon, can you improve on the approximation?