Limits

  • Exponential Trend
    problem
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    Exponential Trend

    Age
    16 to 18
    Challenge level
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    Find all the turning points of y=x^{1/x} for x>0 and decide whether each is a maximum or minimum. Give a sketch of the graph.
  • Spokes
    problem
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    Spokes

    Age
    16 to 18
    Challenge level
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    Draw three equal line segments in a unit circle to divide the circle into four parts of equal area.
  • There's a limit
    problem
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    There's a Limit

    Age
    14 to 18
    Challenge level
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    Explore the continued fraction: 2+3/(2+3/(2+3/2+...)) What do you notice when successive terms are taken? What happens to the terms if the fraction goes on indefinitely?

  • The silhouette of a cartoon witch.
    problem
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    Witch of Agnesi

    Age
    16 to 18
    Challenge level
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    Sketch the members of the family of graphs given by $y = a^3/(x^2+a^2)$ for $a=1, 2$ and $3$.

  • Converging Product
    problem
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    Converging Product

    Age
    16 to 18
    Challenge level
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    In the limit you get the sum of an infinite geometric series. What about an infinite product (1+x)(1+x^2)(1+x^4)... ?
  • Rain or Shine
    problem
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    Rain or Shine

    Age
    16 to 18
    Challenge level
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    Predict future weather using the probability that tomorrow is wet given today is wet and the probability that tomorrow is wet given that today is dry.

  • Discrete Trends
    problem
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    Discrete Trends

    Age
    16 to 18
    Challenge level
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    Find the maximum value of n to the power 1/n and prove that it is a maximum.

  • Reciprocal Triangles
    problem

    Reciprocal Triangles

    Age
    16 to 18
    Challenge level
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    Prove that the sum of the reciprocals of the first n triangular numbers gets closer and closer to 2 as n grows.
  • Lower Bound
    problem

    Lower Bound

    Age
    14 to 16
    Challenge level
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    What would you get if you continued this sequence of fraction sums? 1/2 + 2/1 = 2/3 + 3/2 = 3/4 + 4/3 =
  • Squareflake
    problem

    Squareflake

    Age
    16 to 18
    Challenge level
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    A finite area inside and infinite skin! You can paint the interior of this fractal with a small tin of paint but you could never get enough paint to paint the edge.