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?
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? Correct Answer Both 1 and 2
Concept:
Let z = x + iy be a complex number,
Where x is called the real part of the complex number or Re (z) and y is called the Imaginary part of the complex number or Im (z)
Conjugate of z = z̅ = x - iy
Calculation:
1. The difference of Z and its conjugate is an imaginary number.
Consider z = a + ib ....(i)
conjugate of z = z̅ = a - ib ....(ii)
eq(i) - eq (ii)
z - z̅ = a + ib - a + ib
⇒ 2ib
Thus it is clear that the difference of z and its conjugate is an imaginary number.
2. The sum of Z and its conjugate is a real number.
eq (i) + eq(ii)
z + z̅ = a + ib + a - ib
⇒ 2a
Thus it is clear that the sum of Z and its conjugate is a real number.
So, Both 1 and 2 are correct.