Добавил:
kostikboritski@gmail.com Выполнение курсовых, РГР технических предметов Механического факультета. Так же чертежи по инженерной графике для МФ, УПП. Писать на почту. Дипломы по кафедре Вагоны Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Скачиваний:
41
Добавлен:
12.08.2017
Размер:
2.3 Mб
Скачать

148/ Chapter 13 Symbolic Calculation

4.Type “assume” in the placeholder, followed by a comma.

5.In the placeholder, type “a = real” using [Ctrl] [=] for the Boolean equals.

6. Press [Enter] for the final result.

Assuming that a is a real number, the result is the absolute value of a.

If you leave out the keyword assume, Mathcad returns the result in terms of the complex sign function, csgn, which gives the sign of the real part of a complex number:

Online Help You can find more details about modifiers and keywords in the online Help topic “The Symbolic Toolbar.”

The simplify keyword simplifies expressions using algebraic rules and identities. Figure 13-4 shows more examples of simplify.

Figure 13-4: The simplify keyword simplifies expressions.

Ignoring Previous Definitions

To make Mathcad ignore prior definitions, you must define the variable recursively, such as x := x. This exception is illustrated in Figure 13-5.

 

Mathcad substitutes the value of

 

3 for x before evaluating this

 

expression.

recursive definition

Although x is defined to be 3,

Mathcad ignores that definition

 

 

for symbolic evaluation because

 

of the recursive definition.

 

 

Figure 13-5: Defining a variable in terms of itself makes the symbolic processor ignore previous definitions of that variable.

Соседние файлы в папке doc