Consider the curve .
.
is an operator, meaning “the slope of the tangent of”. So the expression
, meaning
, is not a fraction.
In order words, it means the slope of the tangent of the curve at a point, such as point
in the graph.
The symbol has no relation with the symbol
. It means
as shown in the graph. In other words,
.
The symbol also has no relation with the symbol
. It means the vertical distance between the current point
, where
, and the point
on the tangent line
, where
is the slope of the tangent line. In other words,
or
.
The relationship of and
is that
.
Similarly, for functions of 2 variables:
.
For functions of 3 variables:
— Me@2018-07-15 09:30:29 PM
.
.
2018.07.15 Sunday (c) All rights reserved by ACHK