Math Problem Statement

what is z2=1

Solution

The equation z2=1z^2 = 1 involves solving for zz in the context of complex numbers. Let's break it down step by step.

Solution in the Real Numbers:

If we restrict zz to real numbers, solving z2=1z^2 = 1 is straightforward: z2=1z=±1z^2 = 1 \quad \Rightarrow \quad z = \pm 1 So, z=1z = 1 or z=1z = -1.

Solution in the Complex Numbers:

However, in the complex plane, we treat zz as a complex number: z=x+iyz = x + iy, where xx is the real part and yy is the imaginary part. We can also express it using Euler's formula and polar form: z=reiθz = re^{i\theta} where rr is the magnitude (modulus) of zz and θ\theta is the argument (angle).

The equation z2=1z^2 = 1 implies: r2ei2θ=1r^2 e^{i 2\theta} = 1 Since 11 can be written as ei2kπe^{i 2k\pi} for any integer kk, this gives the following:

  1. r2=1r^2 = 1, so r=1r = 1 (since magnitudes are positive),
  2. 2θ=2kπ2\theta = 2k\pi, so θ=kπ\theta = k\pi.

Thus, the two solutions are: z=ei0=1andz=eiπ=1z = e^{i0} = 1 \quad \text{and} \quad z = e^{i\pi} = -1

So in both real and complex numbers, the solutions are z=1z = 1 and z=1z = -1.

Would you like further details on complex solutions or more questions on this topic?

Related Questions:

  1. How do you solve z2=1z^2 = -1 in the complex plane?
  2. What is the geometric interpretation of the solutions of z2=1z^2 = 1 on the complex plane?
  3. How does Euler's formula relate to solving quadratic equations in the complex plane?
  4. What are the roots of unity, and how do they connect to solving equations like zn=1z^n = 1?
  5. Can you generalize the solution of z2=cz^2 = c for any complex number cc?

Tip: Understanding complex numbers in polar form makes solving quadratic and higher-degree equations much easier!

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Math Problem Analysis

Mathematical Concepts

Algebra
Complex Numbers
Polar Form
Roots of Unity

Formulas

z^2 = 1
Euler's Formula: e^{i\theta}
Polar Form: z = re^{i\theta}

Theorems

Fundamental Theorem of Algebra
Euler's Formula
Roots of Unity Theorem

Suitable Grade Level

Grades 11-12, Early College