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If Z= - bar(Z) , then which one of the f...

If `Z= - bar(Z)` , then which one of the following is correct?

A

A. The real part of z is zero

B

B. The imaginary part of Z is zero

C

C. The real part of Z is equal to imaginary of part

D

D. The sum of real and imaginary parts of Z is Z

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The correct Answer is:
To solve the problem where \( Z = -\overline{Z} \), we will follow these steps: **Step 1: Define the complex number.** Let \( Z = x + iy \), where \( x \) is the real part and \( y \) is the imaginary part of the complex number \( Z \). **Hint:** Remember that a complex number can be expressed in the form \( a + bi \), where \( a \) is the real part and \( b \) is the imaginary part. --- **Step 2: Write the conjugate of \( Z \).** The conjugate of \( Z \) is given by \( \overline{Z} = x - iy \). **Hint:** The conjugate of a complex number changes the sign of the imaginary part. --- **Step 3: Set up the equation.** According to the problem, we have: \[ Z = -\overline{Z} \] Substituting the expressions for \( Z \) and \( \overline{Z} \), we get: \[ x + iy = - (x - iy) \] **Hint:** Make sure to distribute the negative sign correctly when substituting. --- **Step 4: Simplify the equation.** This simplifies to: \[ x + iy = -x + iy \] **Hint:** Combine like terms carefully to isolate real and imaginary parts. --- **Step 5: Equate the real and imaginary parts.** From the equation \( x + iy = -x + iy \), we can equate the real parts and the imaginary parts: 1. Real part: \( x = -x \) 2. Imaginary part: \( iy = iy \) (which is always true) **Hint:** When equating parts, remember that the imaginary parts must be equal, but they do not provide new information in this case. --- **Step 6: Solve for \( x \).** From the equation \( x = -x \), we can add \( x \) to both sides: \[ 2x = 0 \] Thus, we find: \[ x = 0 \] **Hint:** If you have an equation like \( a = -a \), adding \( a \) to both sides is a good way to solve it. --- **Step 7: Conclusion about \( Z \).** Since \( x \) (the real part of \( Z \)) is 0, we conclude that the real part of \( Z \) is 0. **Final Answer:** The correct option is that the real part of \( Z \) is 0. ---
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PUNEET DOGRA-COMPLEX NUMBER-PREVIOUS YEAR QUESTIONS
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  10. If omega is the imaginary cube root of unity, then what is ( 2 -omega ...

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  11. What are the square roots of -2i? ( i=sqrt(-1))

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  12. What is the conjugate of ((1+2i)/(2+i))^(2) ?

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  13. What is the value of 1+i^(2) +i^(4) + i^(6) +"………"i^(100), where i=sqr...

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  14. If omega is a complex cube root of unity, then what is omega^(10) + om...

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  15. What is ((sqrt(3) +i)/(sqrt(3)-i))^(6) equal to, where i = sqrt( -1) ?

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  16. What is the modulus of | (1+2i)/(1-(1-i)^(2))| ?

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  18. If x^(2) + y^(2) =1, then what is ( 1+x+ iy)/( 1+x-iy) equal to ?

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  19. What is the modulus of ( 1+2i)/( 1- ( 1+i)^(2)) equal to ?

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