Write the complex conjugate of the complex number.Then multiply the number by its complex conjugate. $- 1 - \sqrt { 7 } i$
A) $- 1 + \sqrt { 7 } i , 100$
B) $- 1 + \sqrt { 7 } i , 8$
C) $- 1 + \sqrt { 7 } i , - 6$
D) $1 - \sqrt { 7 i } , 100$
E) $1 + \sqrt { 7 } i , 8$

Question

Write the complex conjugate of the complex number.Then multiply the number by its complex conjugate.​ $- 1 - \sqrt { 7 } i$ ​
A)​ $- 1 + \sqrt { 7 } i , 100$
B)​ $- 1 + \sqrt { 7 } i , 8$
C)​ $- 1 + \sqrt { 7 } i , - 6$
D)​ $1 - \sqrt { 7 i } , 100$
E)​ $1 + \sqrt { 7 } i , 8$

Quizplus · Accepted Answer

The complex conjugate of $-1 - \sqrt{7}i$ is $-1 + \sqrt{7}i$. Multiplying the number by its conjugate: $(-1 - \sqrt{7}i)(-1 + \sqrt{7}i) = (-1)^2 - (\sqrt{7}i)^2 = 1 - (-7) = 8$.

Write the Complex Conjugate of the Complex Number −1−7i- 1 - \sqrt { 7 } i−1−7​i

Write the Complex Conjugate of the Complex Number $- 1 - \sqrt { 7 } i$