Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
JenniferSmart1
Group Title
How do I find absolute values of complex numbers?
7i
 one year ago
 one year ago
JenniferSmart1 Group Title
How do I find absolute values of complex numbers? 7i
 one year ago
 one year ago

This Question is Closed

satellite73 Group TitleBest ResponseYou've already chosen the best response.3
pythatgoras \[a+bi=\sqrt{a^2+b^2}\]
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.3
*pythagoras
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.3
in your case \(a=7,b=1\) so you can just about do it in your head
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.3
\[\sqrt{7^2+1^2}=\sqrt{491}=\sqrt{50}=5\sqrt2\]
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.3
not much to memorize, the hypotenuse is the square root of the sum of the squares, as in a right triangle
 one year ago

JenniferSmart1 Group TitleBest ResponseYou've already chosen the best response.0
but what has an "i" to do with a triangle?
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.3
dw:1358396646228:dw
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.3
the complex numbers live in the complex plane the absolute value is the distance from the origin, which you get via pythagoras \[a^2+b^2=h^2\] \[h=\sqrt{a^2+b^2}\]
 one year ago

JenniferSmart1 Group TitleBest ResponseYou've already chosen the best response.0
is the triangle always in that quadrant?
 one year ago

Callisto Group TitleBest ResponseYou've already chosen the best response.2
No, it depends on the complex number. Let a, b = +ve a+bi => quad. I a + bi => quad. II a  bi => quad. III a  bi => quad. IV
 one year ago

JenniferSmart1 Group TitleBest ResponseYou've already chosen the best response.0
ahh good to know...so is "a" and "b" the length of the lines?
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.3
it doesn't make any difference however, what quadrant you are in, it is still \[a+bi=\sqrt{a^2+b^2}\] i just put it there because your number was \(7i\)
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.3
dw:1358397280980:dw
 one year ago

Callisto Group TitleBest ResponseYou've already chosen the best response.2
dw:1358397320522:dw
 one year ago

JenniferSmart1 Group TitleBest ResponseYou've already chosen the best response.0
That makes sense...I just have one more dumb question a+bi....is that the location of the point at the end of that line?
 one year ago

JenniferSmart1 Group TitleBest ResponseYou've already chosen the best response.0
oh no that is the length of the line....durrr..sorry!!!1
 one year ago

JenniferSmart1 Group TitleBest ResponseYou've already chosen the best response.0
the absolute value of a+bi is the length of the line...correct?
 one year ago

Callisto Group TitleBest ResponseYou've already chosen the best response.2
a + bi a = number (coordinate) in the real part b = number (coordinate) in the imaginary part  a+bi  = length of the line => yes, I think (Actually... I haven't learnt it in the lesson yet.. So...)
 one year ago

JenniferSmart1 Group TitleBest ResponseYou've already chosen the best response.0
that's cool...It makes sense to me though. Thanks soo much @Callisto =)
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.3
yes, it is the length of the line, that is, the distance between the complex number \(a+bi\) and the origin
 one year ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.