Quadratic equations

  • 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!
  • Golden Eggs
    problem

    Golden eggs

    Age
    16 to 18
    Challenge level
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    Find a connection between the shape of a special ellipse and an infinite string of nested square roots.
  • Square Mean
    problem

    Square mean

    Age
    14 to 16
    Challenge level
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    Is the mean of the squares of two numbers greater than, or less than, the square of their means?
  • Target Six
    problem

    Target six

    Age
    16 to 18
    Challenge level
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    Show that x = 1 is a solution of the equation x^(3/2) - 8x^(-3/2) = 7 and find all other solutions.
  • Pareq Calc
    problem

    Pareq calc

    Age
    14 to 16
    Challenge level
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    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 lines are 1 unit and 2 units.
  • Plus or Minus
    problem

    Plus or minus

    Age
    16 to 18
    Challenge level
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    Make and prove a conjecture about the value of the product of the Fibonacci numbers $F_{n+1}F_{n-1}$.