Key learning points

1. Sometimes an answer may be best left in an exact form
2. When dealing with right-angled trigonometry, it is important to look at the information you have and can deduce
3. Consider whether Pythagoras' theorem or trigonometric ratios are more efficient to use
4. All models are wrong, but some models are useful

Common misconception

Keywords

• Trigonometric functions - Trigonometric functions are commonly defined as ratios of two sides of a right-angled triangle for a given angle.

• Sine function - The sine of an angle (sin(θ°)) is the y-coordinate of point P on the triangle formed inside the unit circle.

• Cosine function - The cosine of an angle (cos(θ°)) is the x-coordinate of point P on the triangle formed inside the unit circle.

• Tangent function - The tangent of an angle (tan(θ°)) is the y-coordinate of point Q on the triangle which extends from the unit circle.