Complex Analysis : Elementary Functions

Study concepts, example questions & explanations for Complex Analysis

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Example Questions

Example Question #11 : Elementary Functions

Is the above inequality true?

Possible Answers:

Yes it is true for the whole complex plane.

No it is not true.  The statement is false for the entire complex plane.

The truth of the statement depends on the value of .  In other words it is true for some restricted domain of the complex plane.

It is true when:

The truth of the statement depends on the value of .  In other words it is true for some restricted domain of the complex plane.

It is true only for the real line.

The truth of the statement depends on the value of .  In other words it is true for some restricted domain of the complex plane.

It is true only for the pure imaginary line.

Correct answer:

Yes it is true for the whole complex plane.

Explanation:

above are the steps to get the magnitude of the left side of the inequality.

above are the steps to get the magnitude of the right side of the inequality.

Thus  becomes...

now we do algebra...

with this last inequality you can graph the right hand side and see that it is

always  or greater, or you can reason it this way...

Thus the inequality is true for all complex numbers.

Example Question #12 : Elementary Functions

Compute 

Possible Answers:

None of the choices

Correct answer:

Explanation:

Example Question #13 : Elementary Functions

Compute 

Possible Answers:

Correct answer:

Explanation:

 where  is the complex number such that 

Converting into polar coordinates

This gives us 

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