These identities are particularly useful because they allow you to express any trigonometric function in terms of sine and cosine – often the key to solving complex problems.

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. At point P the \(x\)-coordinate is \(\cos{\theta}\) and the ...

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. At point P the \(x\)-coordinate is \(\cos{\theta}\) and the ...

This article compares two algorithms that compute values of the sine and cosine functions using analytic geometry and the unit circle definition of sine and cosine. One algorithm uses chords on the ...