Purchase Solution

Rouche's formula

Not what you're looking for?

Ask Custom Question

(a) How many roots of the equation z^4 − 6z + 3 = 0 have their modulus between 1
and 2?

(b) Find the number of the roots of the equation
z^6 − 5z^4 + 8z − 1 = 0
in the annulus {z : 1 < |z| < 2}

Purchase this Solution

Solution Summary

This shows how to find the number of roots in given equations.

Solution Preview

We apply Rouche's theorem in both instances:

(a) let p(z) = z^4 - 6z + 3;
then for |z| = 2 we have

|p - z^4| = |6z - 3| < 6|z| + 3 = 15 < 16 = ...

Purchase this Solution


Free BrainMass Quizzes
Know Your Linear Equations

Each question is a choice-summary multiple choice question that will present you with a linear equation and then make 4 statements about that equation. You must determine which of the 4 statements are true (if any) in regards to the equation.

Multiplying Complex Numbers

This is a short quiz to check your understanding of multiplication of complex numbers in rectangular form.

Solving quadratic inequalities

This quiz test you on how well you are familiar with solving quadratic inequalities.

Probability Quiz

Some questions on probability

Geometry - Real Life Application Problems

Understanding of how geometry applies to in real-world contexts