Geometric sequences

  • Investigating Pascal's Triangle
    problem

    Investigating Pascal's Triangle

    Age
    7 to 11
    Challenge level
    2 out of 3

    In this investigation, we look at Pascal's Triangle in a slightly different way - rotated and with the top line of ones taken off.

  • Geometric Parabola
    problem

    Geometric Parabola

    Age
    14 to 16
    Challenge level
    3 out of 3

    Explore what happens when you draw graphs of quadratic equations with coefficients based on a geometric sequence.

  • Vanishing point
    problem

    Vanishing Point

    Age
    14 to 18
    Challenge level
    2 out of 3
    How can visual patterns be used to prove sums of series?
  • Proof Sorter - Geometric Sequence
    interactivity

    Proof Sorter - Geometric Sequence

    Age
    16 to 18
    Challenge level
    1 out of 3

    Can you correctly order the steps in the proof of the formula for the sum of the first n terms in a geometric sequence?

  • Ruler
    problem

    Ruler

    Age
    16 to 18
    Challenge level
    1 out of 3

    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?

  • Binary Squares
    problem

    Binary Squares

    Age
    16 to 18
    Challenge level
    2 out of 3

    If a number N is expressed in binary by using only 'ones,' what can you say about its square (in binary)?

  • Generally Geometric
    problem

    Generally Geometric

    Age
    16 to 18
    Challenge level
    2 out of 3

    Generalise the sum of a GP by using derivatives to make the coefficients into powers of the natural numbers.

  • Von Koch Curve
    problem

    Von Koch Curve

    Age
    16 to 18
    Challenge level
    3 out of 3

    Make a poster using equilateral triangles with sides 27, 9, 3 and 1 units assembled as stage 3 of the Von Koch fractal. Investigate areas & lengths when you repeat a process infinitely often.

  • Sum the Series
    article

    Sum the Series

    This article by Alex Goodwin, age 18 of Madras College, St Andrews describes how to find the sum of 1 + 22 + 333 + 4444 + ... to n terms.