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b) <math class="inline">|e^{(2j)}| = \sqrt{(e^2)^2} = e^2</math> ([[User:Clarkjv|Clarkjv]] 18:33, 10 January 2011 (UTC)) | b) <math class="inline">|e^{(2j)}| = \sqrt{(e^2)^2} = e^2</math> ([[User:Clarkjv|Clarkjv]] 18:33, 10 January 2011 (UTC)) | ||
| − | <math class="inline">|e^{(2j)}| = |(cos(2) + j*sin(2))| = \sqrt{(cos(2))^2 + (sin(2))^2} = \sqrt{1} = 1</math> | + | <math class="inline">|e^{(2j)}| = |(cos(2) + j*sin(2))| = \sqrt{(cos(2))^2 + (sin(2))^2} = \sqrt{1} = 1</math> ([[User:cmcmican|cmcmican]] 10:29, 10 January 2011 (UTC)) |
c) <math class="inline">|j| = \sqrt{(0^2+1^2)} = 1 </math>([[User:Clarkjv|Clarkjv]] 18:33, 10 January 2011 (UTC)) | c) <math class="inline">|j| = \sqrt{(0^2+1^2)} = 1 </math>([[User:Clarkjv|Clarkjv]] 18:33, 10 January 2011 (UTC)) | ||
Revision as of 18:26, 10 January 2011
Contents
Compute the Magnitude of the following Complex Numbers
a) $ e^2 $
b) $ e^{2j} $
c) $ j $
What properties of the complex magnitude can you use to check your answer?
You will receive feedback from your instructor and TA directly on this page. Other students are welcome to comment/discuss/point out mistakes/ask questions too!
Answer 1
a) $ |e^2|= \sqrt{(e^2)^2}= e^2 $ (Clarkjv 18:33, 10 January 2011 (UTC))
b) $ |e^{(2j)}| = \sqrt{(e^2)^2} = e^2 $ (Clarkjv 18:33, 10 January 2011 (UTC))
$ |e^{(2j)}| = |(cos(2) + j*sin(2))| = \sqrt{(cos(2))^2 + (sin(2))^2} = \sqrt{1} = 1 $ (cmcmican 10:29, 10 January 2011 (UTC))
c) $ |j| = \sqrt{(0^2+1^2)} = 1 $(Clarkjv 18:33, 10 January 2011 (UTC))
- Instructor's comments: First of all, bravo for being the first to dare to post on the course wiki!!! The answer to a) is correct and the justification is fine, because the number considered is real. However, the approach from a) does not extend to b), because in b) the number is complex. To obtain the magnitude of a complex number, you can multiply it by its complex conjugate and then take the square root of the result. Can somebody please propose a different answer for b)? Please keep the answer above "as is", since it it a very common mistake. The answer and justification of c) are both correct. -pm
Answer 2
write it here.
Answer 3
write it here.
