Graphing Sequences on TI Calculators

Graphing Sequences on TI Calculators Karlie Donald 10-16-08

Question • Solve • 1/3+1/3^2+1/3^3+1/3^4+…..+1/3^n  •  (1/3)^n n=1

Terms • Sequence- 1/3, 1/9, 1/27, 1/81,… • Finite Series- 1/3+1/9+1/27 • Infinite Series-1/3+1/9+1/27+1/81+…

Make a List (L1) 2nd, Stat, Ops, 5:seq( Type in (A,A,1,20,1) Make a List (L2) Sequence- 1/3,1/9,1/27 and scroll over to OPS Hit number 5:seq( Type in (1/3)^x,x,1,20) Hit To make a list hit STAT and edit. Highlight L2 to put an equation to the list (scroll up to L2). Sequence Seq(expression,variable,begin,end,[increment]) 2nd STAT Enter Using Lists

To make L3 Highlight L3(same as with highlighting L2). Hit 2nd Stat, scroll to OPS. Hit number 6:cumsum( Type in L2) Hit enter. Cumulative Sum 1/3=1/3,1/3+1/9=4/9 CumSum under lists 2nd, Stat, OPS, #6 Cont Using Lists

Graph Lists • Use stat plots • Press 2nd, Y= • Press enter, if stat plot is off turn it on • Use scatter plot, • Xlist:L1 • Ylist:L2 Press 2nd, Mode to return to home screen Repeat step 1-4 but with plot2 For step 5 Ylist:L3 Press zoom 9, which is zoomstat

Using Sequence Mode • First change to sequence mode • Press Mode • Scroll down to the line that has Func, Par, Pol, and Seq in it. • Scroll over to Seq and press enter • Then press 2nd, mode to get to the home screen

Press Y= The screen looks different than in Func Mode. U,V,W are functions n is the variable nMin=min value of n U(n)=function one U(nMin)=function u of the min value of n V(n)=function 2 V(nMin)=function v of the min value of n W(n)=function 3 W(nMin)=function w of the min value of n Con’t using sequence mode

Con’t using sequence mode • For our problem • nMin= 1 • U(n)=what we had for L2 • V(n)=what we had for L3

Graphing Sequences on TI Calculators