Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing

This Question is Closed

geerky42 Group TitleBest ResponseYou've already chosen the best response.0
http://lmgtfy.com/?q=How+do+you+find+the+determinant+of+a+3x3+matrix%3F
 one year ago

Kweku Group TitleBest ResponseYou've already chosen the best response.0
I didnt get you.
 one year ago

novagirl114 Group TitleBest ResponseYou've already chosen the best response.0
Do you have a graphing calculator? If so you can input the matrix and the calculator can sovle for the determinant.
 one year ago

geerky42 Group TitleBest ResponseYou've already chosen the best response.0
You edited your question... Just Google it or do what @novagirl114 said. http://lmgtfy.com/?q=How+do+you+find+the+determinant+of+a+4x4+matrix%3F
 one year ago

malevolence19 Group TitleBest ResponseYou've already chosen the best response.0
Cofactor expansion. The same way you do 3x3's. If you have: \[A=\left[\begin{matrix}a_{11} & a_{12} & a_{13}\\ a_{21} & a_{22} & a_{23}\\ a_{31}&a_{32}&a_{33}\end{matrix}\right]\] Then: \[\det(A)=a_{11} \det \left[\begin{matrix}a_{22} & a_{23} \\ a_{32} & a_{33}\end{matrix}\right]a_{12} \det \left[\begin{matrix}a_{21} & a_{23} \\ a_{31} & a_{33}\end{matrix}\right]+a_{13} \det \left[\begin{matrix}a_{21} & a_{22} \\ a_{31} & a_{32}\end{matrix}\right]\] Better notation is my opinion for an nxn matrix is: \[\det(A)=\sum_{i_1,i_2,...,i_n} \epsilon_{i_1,i_2,...,i_n}a_{1,i_1}a_{2,i_2}...a_{n,i_n}\] Where epsilon is the Levi Cevita tensor.
 one year ago

malevolence19 Group TitleBest ResponseYou've already chosen the best response.0
But the only difference for a 4x4 is that the "sub determinants" (i.e., my determinants of 2x2's) will be THREE BY THREES! So you'll need to do a cofactor expansion to get 4, 3x3 determinants and then 4 cofactor expansions to get 3,2x2 determinants for EACH sub determinant.
 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.