Write the complex conjugate of the complex number.Then multiply the number by its complex conjugate.
$- 14 + \sqrt { 13 } i$
A) $- 14 - \sqrt { 13 } i , 209$
B) $14 - \sqrt { 13 } i , 209$
C) $- 14 + \sqrt { 13 } i , 209$
D) $14 + \sqrt { 13 } i , 209$
E) $- 13 - \sqrt { 14 } i , 209$

Question

Write the complex conjugate of the complex number.Then multiply the number by its complex conjugate. 
 $- 14 + \sqrt { 13 } i$  
A)  $- 14 - \sqrt { 13 } i , 209$
B)  $14 - \sqrt { 13 } i , 209$
C)  $- 14 + \sqrt { 13 } i , 209$
D)  $14 + \sqrt { 13 } i , 209$
E)  $- 13 - \sqrt { 14 } i , 209$

Quizplus · Accepted Answer

The complex conjugate of $- 14 + \sqrt { 13 } i$ is $- 14 - \sqrt { 13 } i$, because the sign of the imaginary part changes. Multiplying the number by its complex conjugate, $(- 14 + \sqrt { 13 } i)(- 14 - \sqrt { 13 } i) = 196 + 13 = 209$.

Write the Complex Conjugate of the Complex Number −14+13i- 14 + \sqrt { 13 } i−14+13​i

Write the Complex Conjugate of the Complex Number $- 14 + \sqrt { 13 } i$