Complex numbers with an unknown, fraction equation not getting it right

  • #1
Femme_physics
Gold Member
2,547
1
Attempt solution attached
Manual says the answers is -1 + i
 

Attachments

Answers and Replies

  • #2
eumyang
Homework Helper
1,347
10
The solution you posted,
[tex]z = \frac{2}{1 + i}[/tex]
is not simplified. You know that you can multiply top and bottom by the conjugate, right? Even so, you still won't get the right answer.

EDIT: I think I found it. From the 2nd to 3rd line, on the RHS you have
[tex](2iz + 1)(1 - i) = 2iz - 2iz + 1 -i [/tex]
, which is wrong. It should be
[tex](2iz + 1)(1 - i) = 2iz - 2i^2 z + 1 - i[/tex]
.
 
Last edited:
  • #3
Femme_physics
Gold Member
2,547
1
Thanks for the great catch! :) I wasn't sure I even know how to solve these. Glad to see I didn't do anything horribly wrong. Apparently it's all about treating i and z like x and y, and if i ever gets to the power of 2, just turn into -1. Easy peasy :)

Appreciate you taking the time to spot my carelessness!
 

Related Threads on Complex numbers with an unknown, fraction equation not getting it right

  • Last Post
Replies
2
Views
3K
Replies
1
Views
611
  • Last Post
Replies
12
Views
2K
Replies
5
Views
478
  • Last Post
Replies
7
Views
2K
  • Last Post
Replies
7
Views
3K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
1
Views
2K
Top