Key learning points

1. Reading solutions from trigonometric graphs is the same as reading solutions from any other graph
2. Due to the period, there may be more than one solution
3. It is possible to predict the number of solutions that exist within a given range

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.

• Period (of a function) - For a repeating function, the period is the distance of one repetition of the entire function.