Quadratic equations

  • Two Cubes
    problem

    Two Cubes

    Age
    14 to 16
    Challenge level
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    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 prove you have found all possible solutions.]
  • Good Approximations
    problem

    Good Approximations

    Age
    16 to 18
    Challenge level
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    Solve quadratic equations and use continued fractions to find rational approximations to irrational numbers.
  • Darts and Kites
    problem

    Darts and Kites

    Age
    14 to 16
    Challenge level
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    Explore the geometry of these dart and kite shapes!
  • Golden Construction
    problem

    Golden Construction

    Age
    16 to 18
    Challenge level
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    Draw a square and an arc of a circle and construct the Golden rectangle. Find the value of the Golden Ratio.
  • Symmetrically So
    problem

    Symmetrically So

    Age
    16 to 18
    Challenge level
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    Exploit the symmetry and turn this quartic into a quadratic.
  • Placeholder: several colourful numbers
    problem

    Bird-Brained

    Age
    16 to 18
    Challenge level
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    How many eggs should a bird lay to maximise the number of chicks that will hatch? An introduction to optimisation.
  • Kissing
    problem

    Kissing

    Age
    16 to 18
    Challenge level
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    Two perpendicular lines are tangential to two identical circles that touch. What is the largest circle that can be placed in between the two lines and the two circles and how would you construct it?
  • Cocked Hat
    problem

    Cocked Hat

    Age
    16 to 18
    Challenge level
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    Sketch the graphs for this implicitly defined family of functions.
  • Pent
    problem

    Pent

    Age
    14 to 18
    Challenge level
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    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.
  • 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!