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Difference between revisions of "Argument"

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The argument of a function is the variable (also called the independent variable) on which the value of the function depends.
 
The argument of a function is the variable (also called the independent variable) on which the value of the function depends.
  
The argument of a complex number <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/a/a013/a013240/a0132401.png" />, represented in the plane by the point with coordinates <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/a/a013/a013240/a0132402.png" /> and <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/a/a013/a013240/a0132403.png" />, is the angle <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/a/a013/a013240/a0132404.png" /> of the radius vector <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/a/a013/a013240/a0132405.png" /> of this point with the <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/a/a013/a013240/a0132406.png" />-axis.
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The argument of a complex number $z=x+iy=r(\cos\phi+i\sin\phi)$, represented in the plane by the point with coordinates $x$ and $y$, is the angle $\phi$ of the radius vector $r$ of this point with the $x$-axis. A ''branch'' of the argument is a specification of the range of values for $\phi$, for example, $0 \le \phi < 2\pi$ or $-\pi < \phi \le \pi$.

Latest revision as of 11:49, 1 January 2016

The argument of a function is the variable (also called the independent variable) on which the value of the function depends.

The argument of a complex number $z=x+iy=r(\cos\phi+i\sin\phi)$, represented in the plane by the point with coordinates $x$ and $y$, is the angle $\phi$ of the radius vector $r$ of this point with the $x$-axis. A branch of the argument is a specification of the range of values for $\phi$, for example, $0 \le \phi < 2\pi$ or $-\pi < \phi \le \pi$.

How to Cite This Entry:
Argument. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Argument&oldid=12495