My Math Forum Complex numbers;

 Algebra Pre-Algebra and Basic Algebra Math Forum

December 16th, 2012, 12:42 AM   #1
Newbie

Joined: Dec 2012

Posts: 28
Thanks: 0

Complex numbers;

Help on this, if z=1+i
Attached Images
 image.jpg (61.6 KB, 682 views)

 December 16th, 2012, 01:07 AM #2 Senior Member     Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,211 Thanks: 521 Math Focus: Calculus/ODEs Re: Complex numbers; If $z=1+i$, then what is $\bar{z}$ ?
 December 16th, 2012, 01:11 AM #3 Newbie   Joined: Dec 2012 Posts: 28 Thanks: 0 Re: Complex numbers; Not listed I think that it changes the - to + and + to -
 December 16th, 2012, 01:12 AM #4 Newbie   Joined: Dec 2012 Posts: 28 Thanks: 0 Re: Complex numbers; Conjugation
 December 16th, 2012, 01:14 AM #5 Senior Member     Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,211 Thanks: 521 Math Focus: Calculus/ODEs Re: Complex numbers; Yes, the bar over a complex value represents the conjugate, in this case $\bar{z}=1-i$. So, make the substitutions, then simplify. What do you get?
 December 16th, 2012, 01:21 AM #6 Newbie   Joined: Dec 2012 Posts: 28 Thanks: 0 Re: Complex numbers; Are : (1+i)^2 = 1-1= 0? Or: (1-i)*(1+i)= 1+i-i-i^2= 1+1=2?
 December 16th, 2012, 02:16 AM #7 Senior Member     Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,211 Thanks: 521 Math Focus: Calculus/ODEs Re: Complex numbers; $(1+i)^2=1+2i+i^2=1+2i-1=2i$ You won't need the second product.
 December 16th, 2012, 02:20 AM #8 Newbie   Joined: Dec 2012 Posts: 28 Thanks: 0 Re: Complex numbers; When it is (1-i)^2, what should I do?
 December 16th, 2012, 02:24 AM #9 Senior Member     Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,211 Thanks: 521 Math Focus: Calculus/ODEs Re: Complex numbers; That won't show up either, but you use the square of a binomial as I did above.
 December 16th, 2012, 02:32 AM #10 Newbie   Joined: Dec 2012 Posts: 28 Thanks: 0 Re: Complex numbers; I get this: 2i(1+i-1+i)i+2-2i = 2i(2i)i+2-2i = 2i^2 i +2-2i = 2(-1)i+2-2i = -2i+2-2i = 2-4i Correct??

 Tags complex, numbers

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post jonas Complex Analysis 2 October 13th, 2014 03:03 PM Miran977 Algebra 5 December 16th, 2012 01:03 PM chocolate Algebra 13 June 30th, 2012 01:35 AM Tutu Algebra 11 June 26th, 2012 01:36 PM jakeward123 Complex Analysis 9 February 8th, 2011 01:49 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top