A community for students. Sign up today!
Here's the question you clicked on:
 0 viewing
 one year ago
Find the products AB and BA to determine whether B is the multiplicative inverse of A.?
 one year ago
Find the products AB and BA to determine whether B is the multiplicative inverse of A.?

This Question is Closed

Hoa
 one year ago
Best ResponseYou've already chosen the best response.0I don't know why we have to find the product of AB and then BA. My work is use GaussJordan method to figure out inverse of A and then compare to B. and dw:1360901929122:dw is inverse of A, it is not a multiply matrix of B .

BAdhi
 one year ago
Best ResponseYou've already chosen the best response.0This uses the definition of the multiplicative inverse. ie if and only if, $$AB=BA=I$$ A is the multiplicative inverse of B So find the values of AB and BA and see whether they are equal to identity matrix

phi
 one year ago
Best ResponseYou've already chosen the best response.1Find the products AB and BA They want you to practice multiplying 2 matrices. can you multiply A*B ?

gjhfdfg
 one year ago
Best ResponseYou've already chosen the best response.2The bottom column of B is suppose to be 0 1 1, my mistake. But I multiplied a * b & I got, [1 0 0] [0 1 0] [0 0 1]

phi
 one year ago
Best ResponseYou've already chosen the best response.1OK, the matrix with 1's on the diagonal is the identity matrix (called I (eye)) a * I will give you a also, if you know a * b = I then you know b is the *inverse* of a you also know b*a= I (but I think they want you to multiply it out and see that it is) and we could just as well say a is the *inverse* of b \[ A^{1} A = I \] (People use capital letters for matrices (bold face if you can). the use lower case, bold letters for vectors)

gjhfdfg
 one year ago
Best ResponseYou've already chosen the best response.2Wouldnt it be B = A^1?

phi
 one year ago
Best ResponseYou've already chosen the best response.1you mean "wouldn't it be \[ B = A^{1} \] the 1 is not an exponent, but means *inverse* You can say that. But the inverse of the inverse \[ (A^{1})^{1} = A\] if we take the inverse of both sides \[ B^{1} = (A^{1})^{1} = A \] or \[ A = B^{1} \] which says A is the inverse of B (or vice versa)

gjhfdfg
 one year ago
Best ResponseYou've already chosen the best response.2Ah okay, what would it mean if they "=" had a slash through it?

gjhfdfg
 one year ago
Best ResponseYou've already chosen the best response.2Got it, thank you for the help.!
Ask your own question
Ask a QuestionFind more explanations on OpenStudy
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.