All Exams Test series for 1 year @ ₹349 only
Question

Consider the following inequalities :
I. $1 + 4i > 3 + 2i$
II. $2 + 3i < 3 + 4i$
III. $4 + 3i > 3 + 4i$
where $i = \sqrt{-1}$
How many of the above are valid ?

The correct answer is
None

Analyzing Complex Number Inequalities Validity

The core principle is that standard ordering operators like $>$ (greater than) and $<$ (less than) are not defined for complex numbers if their imaginary parts are non-zero. These operators only apply to real numbers.

Let's examine each inequality based on this principle:

Inequality I: $1 + 4i > 3 + 2i$

  • Complex numbers involve both a real part and an imaginary part.
  • Standard comparison operators ($>$, $<$) are undefined for complex numbers unless they are purely real (imaginary part is zero).
  • Therefore, the inequality $1 + 4i > 3 + 2i$ is not valid.

Inequality II: $2 + 3i < 3 + 4i$

  • Similar to Inequality I, the comparison operator $<$ is not applicable to complex numbers $2 + 3i$ and $3 + 4i$ as they have non-zero imaginary parts.
  • Thus, the inequality $2 + 3i < 3 + 4i$ is invalid.

Inequality III: $4 + 3i > 3 + 4i$

  • Again, the operator $>$ cannot be meaningfully applied to compare the complex numbers $4 + 3i$ and $3 + 4i$.
  • Hence, the inequality $4 + 3i > 3 + 4i$ is invalid.

Conclusion on Validity

Since none of the provided inequalities involving complex numbers are mathematically valid according to standard definitions, the correct count is zero.

  • Inequality I: Invalid
  • Inequality II: Invalid
  • Inequality III: Invalid

Therefore, zero out of the three inequalities are valid.

Was this answer helpful?

Important Questions from Complex Numbers

  1. Which one of the following is a square root of \(-\sqrt{-1} \)?

  2. What are the roots of equation-I ?

  3. Which one of the following is a root of equation-II?

  4. What is the number of common roots of equation-I and equation-II?

  5. If \(z=\frac{1+i √{3}}{1-i √{3}}\) where i = √-1 then what is the argument of z ?

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App