Introduction to Trigonometric Functions - 2.6.9

Use the slider below to plot points on the graphs below. You may need to reduce fractions.
Use the Point tool to plot the values of y=cos(θ), where θ is the measure of an angle in radians.
Use the point tool to plot the values of y=sin(θ), where θ is the measure of an angle in radians.
Check your graphs by clicking on "Algebra" on each graph and typing in the corresponding function next to the plus sign: y=cos(x) on the first graph and y=sin(x) on the second graph.
What do you notice about the two graphs?
Could these graphs represent functions? Explain your reasoning.
[size=150]Looking at the graphs of [math]y=\cos\left(\theta\right)[/math] and [math]y=\sin\left(\theta\right)[/math], at what values of [math]\theta[/math] do [math]\cos\left(\theta\right)=\sin\left(\theta\right)[/math]? [br][/size]
Where on the unit circle do these points correspond to?
Close
– Jacqueline Rutherford, GeoGebra Classroom Activities, IM Algebra 1, Geometry, Algebra 2

Information: Introduction to Trigonometric Functions - 2.6.9