The trigonometric ratios sine, cosine and tangent are used to calculate angles and sides in right angled triangles. We are now going to extend trigonometry beyond right angled triangles and use it to ...

The angles are labelled with capital letters. The opposite sides are labelled with lower case letters. Notice that an angle and its opposite side are the same letter. The sine rule is: \(\frac{a}{\sin ...

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) ...