SL 3.5: Definition of \(\sin x\) and \(\cos x\) in terms of the unit circle; exact values of trigonometric ratios of \(0,\;\dfrac{{\rm{\pi }}}{6},\;\dfrac{{\rm{\pi }}}{4},\;\dfrac{{\rm{\pi }}}{3},\;\dfrac{{\rm{\pi }}}{2}\) and their multiplesI encourage my students to use the unit circle to help them evaluate exact values of trigonometric ratios for certain angles. This may very well occur during a Paper 1 exam when they do not have their GDC. Specifically, I try to train them to mentally visualize the unit circle (or...