Expanding and factorising quadratics

There are 38 NRICH Mathematical resources connected to Expanding and factorising quadratics
Spot the difference
problem

Spot the difference

Age
16 to 18
Challenge level
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If you plot these graphs they may look the same, but are they?
Geometric Parabola
problem

Geometric parabola

Age
14 to 16
Challenge level
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Explore what happens when you draw graphs of quadratic equations with coefficients based on a geometric sequence.
Unit interval
problem

Unit interval

Age
16 to 18
Challenge level
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Can you prove our inequality holds for all values of x and y between 0 and 1?
Powerful Factors
problem

Powerful factors

Age
16 to 18
Challenge level
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Use the fact that: x²-y² = (x-y)(x+y) and x³+y³ = (x+y) (x²-xy+y²) to find the highest power of 2 and the highest power of 3 which divide 5^{36}-1.
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.]
Composite Notions
problem

Composite notions

Age
14 to 16
Challenge level
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A composite number is one that is neither prime nor 1. Show that 10201 is composite in any base.
Mega Quadratic Equations
problem

Mega quadratic equations

Age
14 to 18
Challenge level
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What do you get when you raise a quadratic to the power of a quadratic?
Telescoping Functions
article

Telescoping functions

Take a complicated fraction with the product of five quartics top and bottom and reduce this to a whole number. This is a numerical example involving some clever algebra.