Expert: Sherry Wallin - 12/6/2010

Question
Dear Ms.Sherry,
      Can you please teach me how to graph the values of Sk1-Sk2 ie, Sk1 = 100(1-(11/17)^x)/(1-(11/17))
           Sk2 = 50(1-(14/17)^x)/(1-(14/17)) ,because I dont know how to find the answer of this through graphing calculator.I just know how to convert the calculator to sequence mode.This is the answer of the question which I previously sent you.I tried to ask Mr.Ahmed,but he is taking too much time,or I think he has forgotten to answer me back.Can you please teach me?
                     Thanks a LoT!
                      Bulbul.  

Answer
You can pretend sk1 is y and then plot points like you learned in beginning algebra:


x | y(or sk1) = (1-(11/17)x)/(1-(11/17) = (1-(11/17)x)/(6/17)
______________________________________________________________________
1      1
2     -5/6
3     -1
4     -9/2
...
10    -31/2

As you can see the number is getting more and more negative...
below are the calculations for the first few

x=1 (1-(11/17)1)/(6/17) = (6/17)/(6/17)

x = 2(1-(11/17)2)/(6/17) = (1-(11/17)2)/(6/17) = [1-(22/17)]/(6/17)
= (-5/17)(17/6)= -5/6

x = 3(1-(11/17)3)/(6/17) = (-16/17)(17/6) = -1

x = 4(1-(11/17)4)/(6/17) = (-27/16)(17/6)  = -9/2
x = 10 => y = -31/2

If what you wanted is for me to show you how on the calculator to find these points I can't do that, particularly, if I don't know what calculator you are using.

Math Prof