What can you say about the common difference of an AP where every term is prime?
A quadrilateral changes shape with the edge lengths constant. Show the scalar product of the diagonals is constant. If the diagonals are perpendicular in one position are they always perpendicular?
This is a beautiful result involving a parabola and parallels.
There are many different methods to solve this geometrical problem - how many can you find?
Can you find a way to prove the trig identities using a diagram?
Are these statistical statements sometimes, always or never true? Or it is impossible to say?
Can you work through these direct proofs, using our interactive proof sorters?
Was it possible that this dangerous driving penalty was issued in error?
