Geometric sequences

There are 30 NRICH Mathematical resources connected to Geometric sequences
Generally Geometric
problem

Generally geometric

Age
16 to 18
Challenge level
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Generalise the sum of a GP by using derivatives to make the coefficients into powers of the natural numbers.
Golden Fibs
problem

Golden fibs

Age
16 to 18
Challenge level
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When is a Fibonacci sequence also a geometric sequence? When the ratio of successive terms is the golden ratio!
The Great Tiling Count
problem

The great tiling count

Age
7 to 11
Challenge level
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Compare the numbers of particular tiles in one or all of these three designs, inspired by the floor tiles of a church in Cambridge.
Sierpinski Triangle
problem

Sierpinski triangle

Age
16 to 18
Challenge level
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What is the total area of the triangles remaining in the nth stage of constructing a Sierpinski Triangle? Work out the dimension of this fractal.
Von Koch Curve
problem

Von koch curve

Age
16 to 18
Challenge level
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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.
Investigating Pascal's Triangle
problem

Investigating pascal's triangle

Age
7 to 11
Challenge level
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In this investigation, we look at Pascal's Triangle in a slightly different way - rotated and with the top line of ones taken off.
Production Equation
problem

Production equation

Age
16 to 18
Challenge level
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Each week a company produces X units and sells p per cent of its stock. How should the company plan its warehouse space?
Mobile Numbers
problem

Mobile numbers

Age
5 to 11
Challenge level
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In this investigation, you are challenged to make mobile phone numbers which are easy to remember. What happens if you make a sequence adding 2 each time?
Proof Sorter - Geometric Sequence
interactivity

Proof sorter - geometric sequence

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