complexThe modulus and radiance of are two basic elements of the complex triangular form. The length of the vector corresponding to the complex number is called the amplitude of the complex number. The angle between the vector and the positive direction of the real axis is the radiance of the complex number.The magnitude of the spoke angle is infinite, but the principal value of the spoke angle is uniquely determined.By using the modulus and argument of complex numbers, complex numbers can be expressed as triangular expressions and exponential expressions, and can be transformed with algebraic expressions to facilitate the discussion of different problems.
Chinese name
Radial angle
Foreign name
argument
Directions
Counterclockwise is positive, clockwise is negative
Because of a complex numberCan be determined by an ordered pair of real numbersUniquely determined, and the ordered real number pair andRectangular coordinate system The points in are one-to-one, so you can use the coordinates asPoint ofTo represent the complex number, whenThe points on the axis correspond to real numbers, calledThe axis is real,The point on the axis (except the origin) corresponds to a pure imaginary number, calledThe axis is imaginary, and the plane representing complex numbers like this is calledComplex plane。
complexYou can also use vectorsTo indicate that,AndAre vectorsstayShaft andProjection on the axis.Thus, pluralJust like the vector on the planeA one-to-one correspondence has been established.
vectorThe length of is called complexmodelOr absolute value, recorded as, so
Current pointNot the origin, that is, the complex numberWhen, vectorAndThe included angle in the positive direction of the axis is called complex numberOfRadial angle, recorded as。The symbol of the spoke angle is specified as: turning counterclockwise from the positive real axisPositive, turn clockwiseIs negative.[1]
Principal value of spoke angle
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Obviously a non-zero complex numberThere are infinitely many values for the radiance ofInteger multiple of, butOnly one value inMeet conditions, saidPluralThe main spoke angle of, recorded as, so
WhenWhen,The spoke angle of is meaningless.
complexPrimary and secondary angles ofPrincipal value of arc tangentThere are the following relationships:[1]
Radial angle
Triangular and exponential expressions
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It can be seen from the relationship between rectangular coordinates and polar coordinates that non-zero finite complex numbersCan use its moldAnd spoke angleTo represent, that is
Using Euler formula
have to
The first and third formulas are called non-zero complex numbers respectivelyTriangular expression and exponential expression of, which can be transformed with algebraic expression to facilitate the discussion of different problems.[1]