Trigonometry · Grades 10 to 12
Sine and cosine graphs
Find the period of a wave.
The idea
The sine and cosine functions repeat forever. One full repeat is called the period.
For y = sin(bx) or y = cos(bx), the period is 2π divided by b. A larger b makes the wave repeat faster.
Worked examples
- How to Find the Period of a Sine Function Find the period of y = sin(3x). Three steps with 2pi over b, the reason, and the b-value mistakes to avoid.
- How to Find a Missing Side with Sine Find the opposite side when the angle is 30 degrees and the hypotenuse is 12. Four steps with SOH CAH TOA and the mistakes to avoid.
- How to Convert Degrees to Radians Convert 135 degrees to radians in three steps. See the pi/180 factor, the simplification, and the factor mistakes to avoid.
Practice this topic
3 problems with answers.