Khan Academy Wiki

The Graphs of trigonometric functions exercise appears under the Trigonometry Math Mission and Differential calculus Math Mission. This exercise connects the graph of a trigonometric function with its functional form by both creating the graph and finding the functional form.

Types of Problems[]

There are two types of problems in this exercise:

  1. Write a formula for the trigonometric function: This problem has a graph with a few labeled points. The user is expected to fully write the equation of the trigonometric function in the space provided.
    Gotf1

    Write a formula for the trigonometric function

  2. Create the graph of the trigonometric function: This problem has the formula for a sinusoid. The user is expected to move some points on the graphing manipulative to create the graph of the trigonometric function.
    Gotf2

    Create the graph of the trigonometric function

Strategies[]

Knowledge of the parent functions for sine and cosine and the functional transformations are encouraged to ensure success on this exercise.

  1. The general form of a trig function is .
    1. A is the amplitude of the trig function.
    2. B is the horizontal scale factor, and the period is .
    3. C is the horizontal shift.
    4. D is the vertical shift.
  2. The problems in this exercise do not seem to have horizontal or vertical shifts.

Real-life Applications[]

  1. Sinusoids are used to model periodic behavior, such as the number of hours of daylight, or temperature cycles over a day, or a year.
  2. Light and sound travel in waves that are shaped like sine and cosine curves.
  3. Trigonometry has many applications in astronomy, music, analysis of financial markets, and many more professions.