hielly's maths thread

[Flaming_Arrow]

[Flaming_Arrow]

omg for the first question how do you know when to use the quadratic formula. The formula just pops up.. your a genius THANKS

its when you can't factorise a equation

[cobby]

hey so is equal to ??

yes

[Hielly]

okay this question is on matrixes
Edit- this is q.2 There are 25 seats arranged in five rows and five columns. If 0, 1 respectively are used to
indicate whether a seat is vacant or occupied, write down a matrix which represents the
situation when

If seating arrangements (as in 2) are represented by matrices, consider the matrix in which
the i, j element is 1 if i = j, but 0 if it does not equal to j . What seating arrangement does this matrix
represent?

my teacher couldn't work it out.

thanks

[/0]

What is the size of the matrix? I would think that description fits the identity matrix, where the diagonal from top left to bottom right is all 1s, with every other element 0.

[/0]

For , , so they are all 1. The rest must be zero. (Wonder if I got the Matrix LateX right lol)

[/0]

All the entries in the matrix are given by , where i is the row number and j the column number. It just so happens that when , you get

[Hielly]

matrixes question a=[3  1]
                            [-2 3]

solve the system AX=K where,
K=[0]
    [1]


sorry not good with the latex thingy, i thought doing this would take up less time

thanks

[Flaming_Arrow]

[Hielly]

1)

so far i got up to this step



2)Are the following products, of matrices given in 1, defined?
AY, YA,XY,X^2, CI, XI

[Flaming_Arrow]

do u mean

1)

[Flaming_Arrow]

what do u mean? could you type it out fully?

[Hielly]

1)

so far i got up to this step

[Flaming_Arrow]

1)

[Flaming_Arrow]

thanks!
 find p

first i crossed multiply so
mn+mp=n-p

move n to other side

mn+mp-n=-p

dont know what to do from here