Math Problem Statement

Solution

The text extracted from the image reads:

"If zz and ww are the two complex numbers such that z=wz = \overline{w} and arg(zw)=π\arg\left(\frac{z}{w}\right) = \pi, then arg(z)\arg(z) is:"

Solution

Given the conditions:

  1. z=wz = \overline{w}
  2. arg(zw)=π\arg\left(\frac{z}{w}\right) = \pi

We need to find arg(z)\arg(z).

Steps to Solve

  1. Understanding z=wz = \overline{w}:

    • w\overline{w} is the complex conjugate of ww.
    • If w=a+biw = a + bi, then z=abiz = a - bi.
  2. Using the argument condition arg(zw)=π\arg\left(\frac{z}{w}\right) = \pi:

    • arg(zw)\arg\left(\frac{z}{w}\right) implies that zw\frac{z}{w} is a negative real number because its argument is π\pi.

Let's express zz and ww in polar form:

  • w=reiθw = r e^{i\theta}
  • z=reiθz = r e^{-i\theta} (since z=wz = \overline{w})

Now, compute zw\frac{z}{w}: zw=reiθreiθ=eiθeiθ=e2iθ\frac{z}{w} = \frac{r e^{-i\theta}}{r e^{i\theta}} = e^{-i\theta} e^{-i\theta} = e^{-2i\theta}

For the argument of zw\frac{z}{w} to be π\pi: arg(e2iθ)=π\arg\left(e^{-2i\theta}\right) = \pi

This implies: 2θ=π-2\theta = \pi θ=π2\theta = -\frac{\pi}{2}

  1. Finding arg(z)\arg(z):
    • z=reiθz = r e^{-i\theta}
    • From the above, θ=π2\theta = -\frac{\pi}{2}
    • Thus, arg(z)=θ=(π2)=π2\arg(z) = -\theta = -(-\frac{\pi}{2}) = \frac{\pi}{2}

Conclusion

The argument of zz is π2\frac{\pi}{2}.

Would you like further details or have any questions?

Related Questions

  1. How would the solution change if zz and ww were not conjugates?
  2. Can you explain the concept of complex conjugates in more detail?
  3. How do arguments of complex numbers help in solving equations?
  4. What happens if the argument condition was π2\frac{\pi}{2} instead of π\pi?
  5. How can we visually interpret the arguments on the complex plane?
  6. What are the properties of complex conjugates in general?
  7. Can you demonstrate solving a similar problem with different conditions?
  8. How do we handle complex numbers with real and imaginary parts separately?

Tip

When dealing with arguments of complex numbers, remember that the argument of the product or quotient of two complex numbers is the sum or difference of their individual arguments.

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Math Problem Analysis

Mathematical Concepts

Complex Numbers
Argument of Complex Numbers
Complex Conjugates

Formulas

Polar form of complex numbers

Theorems

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Suitable Grade Level

Undergraduate