Suppose you remember the trianglular numbers, but can't
remember their formula. Enter the following values into
L1: 1, 2, 3 and L2: 1, 3, 6.
Now do a QuadReg L1,L2
using your TI-83+ calculator (STAT, CALC, 5)
and interpret the results.
Answer:
y = ax2+bx+c a=.5 b=.5
which means: ½n(n+1)
Suppose further you really couldn't remember if the relationship
was quadratic. Try a CubicReg L1,L2
and interpret the results.
Answer:
Add an additional point onto the end of
L1: 4 and L2: 10.
Repreform the CubicReg L1,L2
and interpret the results.
Answer:
y = ax3+bx2+cx+d a=d=0 b=.5 c=.5
which means: ½n(n+1)
Try the CubicReg L1,L2
with L1: 1, 2, 3, 4 and L2: 1, 5, 14, 30
(sums of squares) and interpret the results.
Try to express your answer in an aesthetically pleasing form.