Pair indices with values
Calculate the terms first, then plot the ordered pairs as separate points
- Initial point Use index zero for the given starting value \(\displaystyle t_0=5\Rightarrow(0,5)\)
- Next point The next term uses index one \(\displaystyle t_1=8\Rightarrow(1,8)\)
- Discrete points Keep points separate because fractional indices are outside this sequence domain
- Exact reading Use the supplied coordinate key rather than guessing between broad axis ticks
Worked example
Start at 5 and add 3. Find the points for indices 0,1,2,3
- \(\displaystyle t_1=5+3=8\)Point (1,8)
- \(\displaystyle t_2=8+3=11\)Point (2,11)
- \(\displaystyle t_3=11+3=14\)Point (3,14)
- \(\displaystyle (0,5),(1,8),(2,11),(3,14)\)Include the given starting point. Plot four separate points
Common mistakes
Difficulty levels
Questions about this topic
Why are the points separate?+
These sequences have non-negative integer indices. Joining points would suggest values at indices not in the domain
Does selecting a graph prove I can draw one?+
No. Practise plotting the ordered pairs on paper and checking your axes and scale
Can a term value be negative?+
Yes. The vertical value may be negative even though the horizontal index is non-negative
Can I use a calculator?+
A calculator is allowed unless a question is marked no calculator
Which year level and chapter is this?+
Year 11, VCE Units 1 & 2, General Mathematics, chapter 3: Sequences and finance