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

Solve quadratic equations and use continued fractions to find rational approximations to irrational numbers.

Rectangle PQRS has X and Y on the edges. Triangles PQY, YRX and XSP have equal areas. Prove X and Y divide the sides of PQRS in the golden ratio.
A voyage of discovery through a sequence of challenges exploring properties of the Golden Ratio and Fibonacci numbers.

Can you find the maximum value of the curve defined by this expression?

Make a conjecture about the curved track taken by the complex roots of a quadratic equation and use complex conjugates to prove your conjecture.

Find the equation from which to calculate the resistance of an infinite network of resistances.

Make and prove a conjecture about the value of the product of the Fibonacci numbers F{n+1}F{n-1}.

When is a Fibonacci sequence also a geometric sequence? When the ratio of successive terms is the golden ratio!

A rhombus PQRS has an angle of 72 degrees. OQ = OR = OS = 1 unit. Find all the angles, show that POR is a straight line and that the side of the rhombus is equal to the Golden Ratio.

ABCDE is a regular pentagon of side length one unit. BC produced meets ED produced at F. Show that triangle CDF is congruent to triangle EDB. Find the length of BE.

Solve an equation involving the Golden Ratio phi where the unknown occurs as a power of phi.

Find a connection between the shape of a special ellipse and an infinite string of nested square roots.

This polar equation is a quadratic. Plot the graph given by each factor to draw the flower.

Track the roots of quadratic equations as you move the corresponding graphs and discover the transitions from real to complex roots.
This article introduces complex numbers, brings together into one bigger 'picture' some closely related elementary ideas like vectors and the exponential and trigonometric functions and. . . .

Draw a square and an arc of a circle and construct the Golden rectangle. Find the value of the Golden Ratio.

Find all the triples of numbers a, b, c such that each one of them plus the product of the other two is always 2.

Is the mean of the squares of two numbers greater than, or less than, the square of their means?

What is the same and what is different about these circle questions? What connections can you make?

How good are you at finding the formula for a number pattern ?

Show that x = 1 is a solution of the equation x^(3/2) - 8x^(-3/2) = 7 and explain why this is so. Find all the solutions of the equation.

Solve the equation sin z = 2 for complex z. You only need the formula you are given for sin z in terms of the exponential function, and to solve a quadratic equation and use the logarithmic function.

The diagram shows a regular pentagon with sides of unit length. Find all the angles in the diagram. Prove that the quadrilateral shown in red is a rhombus.

Find the sides of an equilateral triangle ABC where a trapezium BCPQ is drawn with BP=CQ=2 , PQ=1 and AP+AQ=sqrt7 . Note: there are 2 possible interpretations.

After transferring balls back and forth between two bags the probability of selecting a green ball from bag 2 is 3/5. How many green balls were in bag 2 at the outset?

A bag contains red and blue balls. You are told the probabilities of drawing certain combinations of balls. Find how many red and how many blue balls there are in the bag.

Two perpendicular lines are tangential to two identical circles that touch. How big is the circle that just fits between the two lines and the two circles and how would you construct it?

A new solution to a Tough Nut problem. Aleksander has drawn graphs for members of the family of functions given by the implicit equation (x^2 + 2ay -a^2)^2 = y^2(a^2 - x^2) corresponding to different. . . .

Find all real solutions of the equation (x^2-7x+11)^(x^2-11x+30) = 1.

If xyz = 1 and x+y+z =1/x + 1/y + 1/z show that at least one of these numbers must be 1. Now for the complexity! When are the other numbers real and when are they complex?

Triangle ABC is an equilateral triangle with three parallel lines going through the vertices. Calculate the length of the sides of the triangle if the perpendicular distances between the parallel. . . .

Draw any triangle PQR. Find points A, B and C, one on each side of the triangle, such that the area of triangle ABC is a given fraction of the area of triangle PQR.

This is an interactivity in which you have to sort the steps in the completion of the square into the correct order to prove the formula for the solutions of quadratic equations.

Two cubes, each with integral side lengths, have a combined volume equal to the total of the lengths of their edges. How big are the cubes? [If you find a result by 'trial and error' you'll need to. . . .