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Consider the following statements in re...

Consider the following statements in respect of an arbitrary complex number Z :
1. The difference of Z and its conjugate is an imaginary number.
2. The sum of Z and its conjugate is a real number.
Which of the above statements is/are correct?

A

1 only

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 an arbitrary complex number \( Z \). Let’s denote the complex number \( Z \) as: \[ Z = a + ib \] where \( a \) and \( b \) are real numbers, and \( i \) is the imaginary unit. ### Step 1: Analyze the first statement The first statement is: "The difference of \( Z \) and its conjugate is an imaginary number." 1. **Find the conjugate of \( Z \)**: The conjugate of \( Z \) is given by: \[ \overline{Z} = a - ib \] 2. **Calculate the difference \( Z - \overline{Z} \)**: \[ Z - \overline{Z} = (a + ib) - (a - ib) = a + ib - a + ib = 2ib \] 3. **Determine the nature of the result**: The result \( 2ib \) is purely imaginary since it has no real part (it is of the form \( bi \) where \( b \) is a real number). Thus, the first statement is **correct**. ### Step 2: Analyze the second statement The second statement is: "The sum of \( Z \) and its conjugate is a real number." 1. **Calculate the sum \( Z + \overline{Z} \)**: \[ Z + \overline{Z} = (a + ib) + (a - ib) = a + ib + a - ib = 2a \] 2. **Determine the nature of the result**: The result \( 2a \) is purely real since it has no imaginary part (it is of the form \( 2a \) where \( a \) is a real number). Thus, the second statement is also **correct**. ### Conclusion Both statements are correct. Therefore, the answer is: **Both statements 1 and 2 are correct.**
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