Texas Instruments TI-84 - Manual (Page 312)

Chapter 12: Statistics 309
LinReg(ax+b) [ Xlistname,Ylistname,freqlist,regequ ]
QuadReg (ax QuadReg (ax QuadReg (ax QuadReg (ax
2
+bx+c) +bx+c) +bx+c) +bx+c)
QuadReg (quadratic regression) fits the second-degree polynomial y=ax
2
+bx+c to the
data. It displays values for a , b , and c ; when DiagnosticOn is set, it also displays a value
for R
2
. For three data points, the equation is a polynomial fit; for four or more, it is a
polynomial regression. At least three data points are required.
QuadReg [ Xlistname,Ylistname,freqlist,regequ ]
CubicReg—(a CubicReg—(a CubicReg—(a CubicReg—(ax xx x
3
+b +b +b +bx xx x
2
+c +c +c +cx xx x+d) +d) +d) +d)
CubicReg (cubic regression) fits the third-degree polynomial y=ax
3
+bx
2
+cx+d to the
data. It displays values for a , b , c , and d ; when DiagnosticOn is set, it also displays a
value for R
2
. For four points, the equation is a polynomial fit; for five or more, it is a
polynomial regression. At least four points are required.
CubicReg [ Xlistname,Ylistname,freqlist,regequ ]
QuartReg—(a QuartReg—(a QuartReg—(a QuartReg—(ax xx x
4
+b +b +b +bx xx x
3
+c +c +c +cx xx x
2
+ dx+e) + dx+e) + dx+e) + dx+e)
QuartReg (quartic regression) fits the fourth-degree polynomial y=ax
4
+bx
3
+cx
2
+dx+e to
the data. It displays values for a , b , c , d , and e ; when DiagnosticOn is set, it also displays
a value for R
2
. For five points, the equation is a polynomial fit; for six or more, it is a
polynomial regression. At least five points are required.