Quadratictn = an2 + bn + c

Ex: Find the generating function for the following:

A) 2, 7, 16, 29, 46, 67, . . .

3204/5 students can do a Quad Reg on the graphing calculator

Calculator

To find a sequence from a ruleStat1:EditL1=2nd List OPS 5:SeqSeq(2x2+x,x,1,6)To find a sequence of differenceL2=2nd List OPS 7: List(L1)Back

Line of Best Fit on TI-83s(84s)

• Regression is a statistical method that is used to produce an equation that models data.

• The TI-83s can do regressions for:– linear, – quadratic, – cubic, – sinusoidal, – exponential, – and logarithmic data.

• To determine how close the equation matches the data the calculator provides a correlation coefficient

• We use R2

– Go to Catalogue to turn Diagnostic On

• If R2 is close to 1, the model is a near perfect match to the data.

• If R2 is close to 0, the model is NOT a very good match to the data.– This would mean that you should try a

different regression.

To do a regression on the TI-83

• Enter your data into the lists

• STAT

• 1:edit

• L1 will contain the sequence position

• L2 will contain the sequence

L1 L2

1 2

2 7

3 16

4 29

5 46

6 67

To determine the type of regression, plot the data.

• Look back to first handout.

• What does the data look like??– Parabola

• Quadratic regression

• What is the generating function?tn = 2n2 – n + 1

• What is r2?1. The function is a perfect match!