What is least positive argument of a comlex number?

Dear abinash,...

for this complex number question for arguments...there is a general derivation,,plz go thru it 

Given any complex numbers (called coefficients) a₀, ..., a_n, the equation

has at least one complex solution z, provided that at least one of the higher coefficients, a₁, ..., a_n, is nonzero. This is the statement of the fundamental theorem of algebra. Because of this fact, C is called an algebraically closed field. This property does not hold for the field of rational numbers Q (the polynomial x² − 2 does not have a rational root, since √2 is not a rational number) nor the real numbers R (the polynomial x² + a does not have a real solution for a > 0, since the square of x is positive for any real number x).

There are various proofs of this theorem, either by analytic methods such as Liouville's theorem, or topological ones such as the winding number, or a proof combining Galois theory and the fact that any real polynomial of odd degree has at least one root.

Because of this fact, theorems that hold "for any algebraically closed field", apply to C.