Recent content by LaraCroft

Homework Statement How do I determine the distance between the parallel planes 2x-4y+ 2z = 5 and -2x+4y-2z= -9: ___? Homework Equations The Attempt at a Solution I got 1/4, but I think that is wrong. Any help would be great!

Homework Statement If a 4x4 matrix A with rows v1, v2, v3 and v4 has determinant detA =-2 then then det (v1, 9v2+5v3, 5v2+8v3, v4) =___? Homework Equations The Attempt at a Solution Ok, so I think it should be -18 (since 9 x -2). I mean the determinant should not change...

Homework Statement If the determinant of a 3 x 3 matrix A is det(A) = 10, and the matrix B is obtained by multiplying the third row by 8, then det(B) = ___? If the determinant of a 5 x 5 matrix A is det(A) = 9, and the matrix C is obtained from A by swapping the second and fourth rows, then...

Actually...no.. is it exponential multiplication?

Homework Statement So, if the problem asks... Find the elementary matrices such that the respective matrix equation holds...what do I do? [_ _ _] [4 4 -1] [4 4 -1 ] [_ _ _] [4 -1 -5] = [4 -1 -5] [_ _ _] [-4 1 4] [-12 3 12] Does this mean to find a...

How do I work with a matrix like this?? Homework Statement How do I go about solving a matrix like this: [ 3e^4t -2e^3t ] [ 4e^4t -5e^3t ] Like how would I get the determinant and stuff? Do I avoid the exponent looking things, or get rid of them somehow?? Please help...

Homework Statement If A = [ -4e^4t sin(9t) -4e^5t cos(9t) ] [ 4e^4t cos(9t) 4e^5t sin(9t) ] then what would A^-1 be? I think I am mainly confused with the cos's and sin's...and all that other junk...since I know how to get the inverse of a regular matrix! Thank you...

Let A = [ -3 9 ] [ -1 3 ] Find two 2x2 matrices B and C, such that AB = AC BUT B does not equal C. I am stumped, but I am trying inverses and such, with no luck :( Any insight would be great!:wink:

Homework Statement If A = [ -4e^4t sin(9t) -4e^5t cos (9t) ] [ 4e^4t cos (9t) -4te^5t sin (9t) ] then A^-1 = [ ___ ___ ] [ ___ ___ ] Homework Equations how do you deal with the exponents? The Attempt at a Solution Put into RREF, and then see what the inverse is?

Homework Statement Let A = [ 3 2 ] [ 6 7 ] Find the following: (a) det (A) = __ (b) the matrix of cofactors C = (__, __) (__, __) (c) adj (A) = (__, __) (__, __) (d) A^-1 = (__,__) (__, __) Homework Equations I am just not to familiar with what cofactor means, and...

Hey, Just stumbled into some linear algebra questions in my textbook...that I can't quite seem to work out... Prove or disprove the following statements concerning 2 x 2 matrices: 1) If A^2 - 3A- 2I = 0 then (A-1) and (A-2I) are both invertible. (so I got the determinant to be 0...

Linear algebra question... Hello again! Ok...so if I let A = [0 1 0 ] [1 1 -2] [2 3 -3] How would I find A^-1? Is that the notation for inverse? Also, could I express A^-1 as a product of at most five elementary matrices? What does this mean exactly? Thanks!:smile:

Ok... Firstly, thank you everyone for responding... Secondly, I am still not getting how to determine all the values of K, so that the matrix (call it A) is the augmented matrix of a system with infinitely many solutions. How would I find all values of K? I understand that I need to row...

How would one determine the values of k such that the following matrix is the augmented matrix of a system with infinitely many solutions: [ (k + 2) -2 1 | 2 ] [ (k + 3) (k+ 3) 2 | 2 ] [ (k + 2) -2 (k -1 ) | -3 ] Also, how would I get all values of k such that the matrix for the...