How to display the unit circle and corresponding trig graphs on a GDC (graphical display calculator). This explanation uses the TI-82/83/84 calculators.

1. Press MODE and select RADIAN, PAR, SIMUL.
2. Press Y= and enter X1T=cos(T), Y1T=sin(T), X2T=T, Y2T=sin(T).
3. Press WINDOW and set Tmin=0, Tmax=6.28,Tstep=0.1, Xmin=-2, Xmax=7.4, Xscl=1.57,Ymin=-3.1, Ymax=3.1, Yscl=1
4. Press GRAPH

The unit circle and the graph of y=sin x will be displayed simultaneously. Use your GDC to do the same for cos x and tan x.

Click Start to see the graph of the sine function being drawn from the unit circle definition. The cosine wave can be produced in the same way. The tangent wave has very different characteristics.