I logarithmic regression graph, I exponential regression graph – Casio FX-9750GII User Manual
Page 152
6-12
Cubic regression
Model formula.......
y
=
ax
3
+
bx
2
+
cx
+
d
a
.......... regression third coefficient
b
.......... regression second coefficient
c
.......... regression first coefficient
d
.......... regression constant term
(
y
-intercept)
Quartic regression
Model formula.......
y
=
ax
4
+
bx
3
+
cx
2
+
dx
+
e
a
.......... regression fourth coefficient
b
.......... regression third coefficient
c
.......... regression second coefficient
d
.......... regression first coefficient
e
.......... regression constant term (
y
-intercept)
I Logarithmic Regression Graph
Logarithmic regression expresses
y
as a logarithmic function of
x
. The standard logarithmic
regression formula is
y
=
a
+
b
× In
x
, so if we say that X = In
x
, the formula corresponds to
linear regression formula
y
=
a
+
b
X.
(CALC)(E)(Log)
(DRAW)
The following is the logarithmic regression model formula.
y
=
a
+
b
·ln
x
a
.............. regression constant term
b
.............. regression coefficient
I Exponential Regression Graph
Exponential regression expresses
y
as a proportion of the exponential function of
x
. The
standard exponential regression formula is
y
=
a
×
e
bx
, so if we take the logarithms of both
sides we get In
y
= In
a
+
bx
. Next, if we say Y = In
y
, and A = In
a
, the formula corresponds to
linear regression formula Y = A +
bx
.
(CALC)(E)(Exp)
(
aeˆbx
) or
(
abˆx
)
(DRAW)
The following is the exponential regression model formula.
y
=
a
·
e
bx
a
.............. regression coefficient
b
.............. regression constant term
y
=
a
·
b
x
a
.............. regression constant term
b
.............. regression coefficient
Quadratic regression
Model formula.......
y
=
ax
2
+
bx
+
c
a
.......... regression second coefficient
b
.......... regression first coefficient
c
.......... regression constant term
(
y
-intercept)