Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
monroe17
Group Title
If A= x 3
y 3
(matrix) determine the values of x and y for which A^2=A
 one year ago
 one year ago
monroe17 Group Title
If A= x 3 y 3 (matrix) determine the values of x and y for which A^2=A
 one year ago
 one year ago

This Question is Closed

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
did you square it?
 one year ago

monroe17 Group TitleBest ResponseYou've already chosen the best response.0
like 3^2?
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
i mean square the matrix
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
i got \[\left[ \begin{array}{ c c } x^2+3y & 3x+9 \\ xy+3y & 3y+9 \end{array} \right]\]
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
assuming the matrix is \[\left[ \begin{array}{ c c } x & 3 \\ y & 3 \end{array} \right]\]
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
that means \[3x+9=3\] so \[x=2\] and also \(y=2\)
 one year ago

monroe17 Group TitleBest ResponseYou've already chosen the best response.0
once you square the matrix, how do you determine the x and y values though?
 one year ago

monroe17 Group TitleBest ResponseYou've already chosen the best response.0
oh nevermind. how'd you get 3x+9=3
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
you have \[\left[ \begin{array}{ c c } x^2+3y & 3x+9 \\ x^2+3y & 3y+9 \end{array} \right]=\left[ \begin{array}{ c c } x & 3 \\ y& 3 \end{array} \right]\]
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
assuming my squaring is correct
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
so that means each entry has to be the same for the matrices to be equal
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
therefore \(3x+9=3\implies x=2\) and \(3y+3=3\implies y=2\) and so the matrix must be \[\left[ \begin{array}{ c c } 2 & 3 \\ 2 & 3 \end{array} \right]\] by substituting back
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
sorry i meant \(3y+9=3\implies x=2\)
 one year ago

monroe17 Group TitleBest ResponseYou've already chosen the best response.0
ohhh okay!
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
you can check that this is right by squaring and seeing that you get the same matrix back
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
also you might want to check that i squared the matrix correctly, but i think it is right
 one year ago

satellite73 Group TitleBest ResponseYou've already chosen the best response.1
gotta run
 one year ago

monroe17 Group TitleBest ResponseYou've already chosen the best response.0
okay:) So, the steps to a problem like this is to first follow the formula (A^2=A) for the matrix. Then just solve..
 one year ago

monroe17 Group TitleBest ResponseYou've already chosen the best response.0
when it said A^2=A I first thought it mean like x^2 and 3^2.. i haven't learned this yet lol
 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.