User Manual

6-19
k Logarithmic Regression Graph
Logarithmic regression expresses y as a logarithmic function of x . The standard logarithmic
regression formula is y = a + b × ln x , so if we say that X = ln x , the formula corresponds to
linear regression formula y = a + b X.
1(CALC) 6( g) 2(Log)
6(DRAW)
The following is the logarithmic regression model formula.
y = a + b ·ln x
a
..............regression constant term
b .............. regression coefficient
k 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 ln y = ln a + bx . Next, if we say Y = ln y , and A = ln a , the formula corresponds to
linear regression formula Y = A + bx .
1(CALC) 6( g) 3(EXP)
1( ae
bx
) or 2( ab
x
)
6(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