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anonymous
 3 years ago
Find the products AB and BA to determine whether B is the multiplicative inverse of A.?
anonymous
 3 years ago
Find the products AB and BA to determine whether B is the multiplicative inverse of A.?

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anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0dw:1360900484563:dw

anonymous
 3 years 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
 3 years 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
 3 years 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 ?

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0The 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
 3 years 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)

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0Wouldnt it be B = A^1?

phi
 3 years 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)

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0Ah okay, what would it mean if they "=" had a slash through it?

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0Got it, thank you for the help.!
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