Складові культури спілкування

Дата добавления: 2015-09-15; просмотров: 470

You’ve seen Mathcad engaging in numeric calculations. This means that whenever you evaluate an expression, Mathcad returns one or more numbers, as shown at the top of Figure 14-1. When Mathcad engages in symbolic mathematics, however, the result of evaluating an expression is generally another expression, as shown in the bottom of Figure 14-1.

Figure 14-1: A numeric and symbolic evaluation of the same expression.

Example 1: Factoring and expanding expressions

Enter an expression. Press the space bar until the entire expression is boxed.

Select Symbolics - Expand or Symbolics - Factor to expand or factor the expression.

Boxing (x 1).(x 4) and then selecting Symbolics - Expand yields: x2 5.x 4

Boxing x2 5.x 4 and then selecting Symbolics - Factor yields: (x 1).(x 4)

Example 2: Evaluating symbolic expressions

Two method is illustrated below:

1) Using Symbolics - Evaluate - Symbolically from the main menu

and then selecting Symbolics - Evaluate - Symbolically yields:

Example 3: Simplyfing symbolic expressions

Enter an expression. Press the space bar until the entire expression is boxed.

Select Symbolics - Simplify.

Example 4: Solving symbolic equations using a SOLVE BLOCK

There are two main differences from a regular Solve Block:

1) Do not use initial guesses.

2) Use the symbolic evaluation operator (right arrow) with the Find function.