Difference between revisions of "Comments:Complex Numbers"

Revision as of 19:08, 29 May 2012

Workaround: IsComplex[]

Sometimes you may want to check if a number is treated as complex number in GeoGebra, as function such as x() and y() do not work with real numbers. As there is no such command as IsComplex you currently have to employ a small trick to check if the number a is complex: complex = IsDefined[sqrt(a) + sqrt(-a)] ∧ (a ≠ 0).

Note: Complex with imaginary part 0, like a = 2 + 0i, also pass this test. If you just want to check if the imaginary part of a complex number a is not 0 you can use y(a) != 0.

bs:Kompleksni brojevi ca:Nombres complexos cs:Komplexní čísla da:Komplekse tal de:Komplexe Zahlen es:Números Complejos et:Kompleksarvud fa:اعداد مختلط fr:Nombres complexes hr:Kompleksni brojevi is:Tvinntölur it:Numeri complessi kk:Кешен сандар ko:복소수 lt:Kompleksiniai skaičiai mk:Комплексен Број pl:Liczby zespolone sk:Komplexné čísla sl:Kompleksna števila tr:Karmaşık Sayılar zh:複數

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-{{note|1=
-Sometimes you may want to check if a number is complex or real, as function such as x() and y() do not work with real numbers. As there is no such command as <code>IsComplex</code> you currently have to employ a small trick to check if the number <code>a</code> is complex: <code>complex = IsDefined[sqrt(a) + sqrt(-a)] ∧ (a ≠ 0)</code>. This works because just complex numbers have both positive and negative square roots (except for 0 which needs a special case).}}
+== Workaround: IsComplex[] ==
+Sometimes you may want to check if a number is treated as complex number in GeoGebra, as function such as <code>x()</code> and <code>y()</code> do not work with real numbers. As there is no such command as <code>IsComplex</code> you currently have to employ a small trick to check if the number <code>a</code> is complex: <code>complex = IsDefined[sqrt(a) + sqrt(-a)] ∧ (a ≠ 0)</code>.
+{{note|1=Complex with imaginary part 0, like <code>a = 2 + 0i</code>, also pass this test. If you just want to check if the imaginary part of a complex number <code>a</code> is not 0 you can use <code>y(a) != 0</code>.}}
 [[bs:Kompleksni brojevi]]