Graph parametric equations
Draw a curve from x(t) and y(t), such as a circle from cos t and sin t.
A parametric curve gives x and y separately as functions of a third value t. For a circle of radius r, use x = r cos t and y = r sin t.
In the examples the trace cursor starts at t = 0, which is the point (r, 0) on the right of the circle.
Classic Graphing 84
Start on the main screen: Press 2nd then mode (QUIT) to get back to the home screen. Pressing clear on a menu also backs out of it.
Open the mode screen. Move down to the graph-type row and move right onto PAR. Press enter, then leave the mode screen.
mode▼▼▼▶enter2ndQUITmodePress y=. Type cos(T) for X1T, press down, and type sin(T) for Y1T. The T key is the X,T,θ,n key.
y=cosX,T,θ,n)▼sinX,T,θ,n)Press graph to draw it, then trace.
graphtrace
You should seeX1T=cos(T) T=0 X=1 Y=0
Classic Graphing 84 key reference · Classic Graphing 84 manual
Natural Color Graphing
Start on the main screen: Press MENU then 1 to open Run-Matrix, the main calculation screen. Press EXIT to back out of a bar or screen, and SHIFT then EXIT (QUIT) to return to the app start.
Open the Graph app. Press F3 (TYPE), then F3 again for parametric.
MENU3F3F3Type 2 cos(T), EXE, then 2 sin(T), EXE. Press F6 to draw and F1 to trace.
2cosX,θ,T)EXE2sinX,θ,T)EXEF6F1
You should seeT=0 X=2 Y=0
Natural Color Graphing key reference · Natural Color Graphing manual
Classic CAS
Start on the main screen: Press home to open the Home menu (Calculator, Graphs, Settings, and more). Choose Calculator, or press esc to go back to the calculation page.
Go to the graphs page with doc. Open the menu, choose 5, Graph Type, then 2, Parametric.
docmenu52Type cos(t) for x1, press down, type sin(t) for y1 and press enter.
cost)▼sint)enter
You should seex1(t)=cos(t) t=0 x=1 y=0
Tips
- To see a true circle, use a square zoom so x and y have the same scale.
- The t step controls how smooth the curve is. Smaller steps are smoother but slower.