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Let C be the set of complex number and z...

Let C be the set of complex number and `z_(1),z_(2)` are in C.
1. agr `(z_(1))=agr(z_(2))impliesz_(1)=z_(2)`
2. `|z_(1)|=|z_(2)|impliesz_(1)=z_(2)`
Which of the statements givben above is/are correct?

A

1only

B

2 only

C

Both 1 and 2

D

neither 1 nor 2

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the two statements regarding complex numbers \( z_1 \) and \( z_2 \). ### Step 1: Analyze the first statement The first statement is: 1. If \( \text{arg}(z_1) = \text{arg}(z_2) \), then \( z_1 = z_2 \). Let \( z_1 = a_1 + i b_1 \) and \( z_2 = a_2 + i b_2 \). The argument of a complex number is defined as: \[ \text{arg}(z) = \tan^{-1}\left(\frac{b}{a}\right) \] Thus, if \( \text{arg}(z_1) = \text{arg}(z_2) \), we have: \[ \tan^{-1}\left(\frac{b_1}{a_1}\right) = \tan^{-1}\left(\frac{b_2}{a_2}\right) \] This implies: \[ \frac{b_1}{a_1} = \frac{b_2}{a_2} \] However, this does not necessarily mean that \( a_1 = a_2 \) and \( b_1 = b_2 \). For example, if \( z_1 = 1 + 3i \) and \( z_2 = 2 + 6i \), both have the same argument, but they are not equal. Therefore, the first statement is **false**. ### Step 2: Analyze the second statement The second statement is: 2. If \( |z_1| = |z_2| \), then \( z_1 = z_2 \). The modulus of a complex number is given by: \[ |z| = \sqrt{a^2 + b^2} \] So, if \( |z_1| = |z_2| \), we have: \[ \sqrt{a_1^2 + b_1^2} = \sqrt{a_2^2 + b_2^2} \] Squaring both sides gives: \[ a_1^2 + b_1^2 = a_2^2 + b_2^2 \] This means that the sum of the squares of the real and imaginary parts of \( z_1 \) and \( z_2 \) are equal. However, this does not imply that \( a_1 = a_2 \) and \( b_1 = b_2 \). For example, \( z_1 = 1 + i \) and \( z_2 = -1 - i \) both have a modulus of \( \sqrt{2} \) but are not equal. Therefore, the second statement is also **false**. ### Conclusion Both statements are false. Thus, the answer is that neither statement is correct.

To solve the problem, we need to analyze the two statements regarding complex numbers \( z_1 \) and \( z_2 \). ### Step 1: Analyze the first statement The first statement is: 1. If \( \text{arg}(z_1) = \text{arg}(z_2) \), then \( z_1 = z_2 \). Let \( z_1 = a_1 + i b_1 \) and \( z_2 = a_2 + i b_2 \). The argument of a complex number is defined as: \[ ...
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