Question

What is the conjugate of \[-a - b\]

Answer 1

Hint: Conjugate is found for complex numbers. Check whether the given number is a complex number or not. Then we need to change the sign of the imaginary part of the complex number.

Complete step by step answer:
The given term is \[-a - b\]
Do we have real parts and imaginary parts?
Real part is the one which is free from the letter ‘i'
So the real part is \[-a - b\]
Imaginary part is 0.
Whenever conjugate is asked we should change the sign of the imaginary part.
But in the above given problem we have only real numbers. No imaginary part to change the sign
The given problem can be written as a complex number as
\[\left( { - a - b} \right){\text{ }} + {\text{ }}0i\]
Where (-a-b) is a real number and 0 is the imaginary number.
As we know we need to change the sign of the imaginary part to find conjugate we can write
Conjugate of \[\left( { - a - b} \right){\text{ }} + {\text{ }}0i\]as \[\left( { - a - b} \right){\text{ - }}0i\]
Zero does not make much sense of writing or not writing so
We can write conjugate as \[-a - b\]

Note: Don’t change the sign of the second term mechanically , conjugate is the sign changing of the imaginary part not the second term .
Complex number is a combination of real number and an imaginary number
The term without i is called real part and the term with i is called imaginary. Sometimes only imaginary parts will be given but still we can express it as a complex number by taking 0 as the real number.