The graph of y = tan θ As the point P moves anticlockwise round the circle, the values of cos θ and sin θ change, therefore the value of tan θ will change. This graph has a period of 180°.

Cosine and sine of an angle θ are defined to be the x and y-coordinates of the point P on the unit circle with the property that the line from O to P makes and angle θ with the positve x-axis. cos(θ) ...

Trigonometry - Edexcel Trigonometric graphs - Higher The three trigonometric ratios; sine, cosine and tangent are used to calculate angles and lengths in right-angled triangles.