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

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.

Common misconception