Stage 5 Investigations

What's the chance of a pair of lists of numbers having sample correlation exactly equal to zero?

Explore the properties of this different sort of differential equation.

Explore the properties of combinations of trig functions in this open investigation.

What can you create using 140 characters and our cool Twilgo environment?

Can you find some Pythagorean Triples where the two smaller numbers differ by 1?

How would you judge a competition to draw a freehand square?

Investigate constructible images which contain rational areas.