Help - VCAA Exam 2 - Module 1 - Qbiii.

[odessa]

I've looked at the examiners report and i still don't understand how it can = 30

the question is:
This different equation indicates that there is a maximum charge which motorists who use toll pass B may pay. What is this maximum charge?
The difference equation is stated in an earlier question as: Bn+1 = 0.9Bn +3 , where B1 = 5

any help pleases?

[odessa]

I can't edit the post for some reason so I'm saying here that it's the 2010 Exam 2!

[DannyN]

you can generate a sequence using spreadsheet on your cas calculator, scroll down and it'll eventually reach $30. You'll see a whole bunch of 29.9999... because in reality it approaches $30 but will never reach it. what calculator do you have?


or... instead of generating a sequence you can sub Bn+1 and Bn as x, since they are approaching inifinity, therefore the number of terms in Bn+1 is equal to the number of terms in Bn
so          x=0.9x+3,   therefore x=30