ACT® · Math: Functions — Trigonometric Functions
The Sine, Cosine and Tangent Graphs Traced from the Circle
Watch it explained
- How it worksHow does the cosine graph come out as the sine graph shifted a quarter turn?
- Worked exampleGraph y = sin(x) from 0 to 2pi and mark every zero, peak and trough.
- Worked exampleFind tan(45 degrees), tan(89 degrees) and tan(89.9 degrees) and watch the blow-up happen.
- Common mistakeWhy doesn't the tangent graph look like a wave the way sine and cosine do?
- Going furtherWhat happens to the sine graph once the angle keeps climbing past 2pi?
Check yourself
Your turneasy1 of 3
Find tan(79 degrees), rounded to three decimal places.End of topic.