Quadratic equations

There are 39 NRICH Mathematical resources connected to Quadratic equations
Golden Ratio
problem

Golden Ratio

Age
16 to 18
Challenge level
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Solve an equation involving the Golden Ratio phi where the unknown occurs as a power of phi.
Power Quady
problem

Power Quady

Age
16 to 18
Challenge level
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Find all real solutions of the equation (x^2-7x+11)^(x^2-11x+30) = 1.
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.
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.
How old am I?
problem

How old am I?

Age
14 to 16
Challenge level
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In 15 years' time my age will be the square of my age 15 years ago. Can you work out my age, and when I had other special birthdays?
Always Two
problem

Always Two

Age
14 to 18
Challenge level
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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.
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.
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!
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.
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?