MEANING OF DIFFERENTIATION
79
If the curve slopes up steeper than (Fig. 9), will be greater than .
Fig. 9. |
Fig. 10. |
If the curve slopes up very gently, as in Fig. 10, will be a fraction smaller than .
For a horizontal line, or a horizontal place in a curve, , and therefore .
Fig. 11.
If a curve slopes downward, as in Fig. 11, will be a step down, and must therefore be reckoned of