Page 440 - Excel for Scientists and Engineers: Numerical Methods

APPENDIX 4 EQUATIONS FOR CURVE FITTING 417

0.00 '

0 5 10
WSI
Figure A4-12. Double-reciprocal plot of enzyme kinetics.
The curve follows equation A4-10 with V,,, = 50, K,,, = 0.5.

Logistic Function. The logistic equation or dose-response curve
1
y=- (A4-11)
1 + e-"
produces an S-shaped curve like the one shown in Figure A4-13.

Y

-10 -5 0 5 10
X

Figure A4-13. Simple logistic curve.
The curve follows equation A4- 1 1 with a = 1.