Cosine and sine of an angle θ are defined to be the x and y-coordinates of the point P on the unit circle with the property that the line from O to P makes and angle θ with the positve x-axis. cos(θ) ...

In support of efforts to foreground functions as central objects of study in algebra, this study provides evidence of how secondary students use trigonometric functions in contextual tasks. The author ...

https://doi.org/10.4169/college.math.j.45.1.011 https://www.jstor.org/stable/10.4169/college.math.j.45.1.011 Summary In textbooks, the familiar sine and cosine ...