Trigonometric graphs - Higher This circle has the centre at the origin and a radius of 1 unit. The point P can move around the circumference of the circle.

Revise trigonometric ratios of sine, cosine and tangent and calculate angles in right-angled triangles with this Bitesize GCSE Maths Edexcel guide.

Interestingly enough, the trigonometric functions that define those relationships are also closely tied to circles. Needless to say, this makes trig one of the hardest topics in math for students ...