P6 ... say what ? ...

7a was worded quiet awkwardly. I assumed that |W|=1, then as normal worked ot that y=x, i.e argument(Pi/4). How did you do the matrix question? I got k as 18, p as 3, a as 1, b as 4 and c as -1. The determinant with these values was zero though which doesn't seem right.

Reply 21

It'sPhil...

2

786

7a was worded quiet awkwardly. I assumed that |W|=1, then as normal worked ot that y=x, i.e argument(Pi/4). How did you do the matrix question? I got k as 18, p as 3, a as 1, b as 4 and c as -1. The determinant with these values was zero though which doesn't seem right.

k was 18, p was 3 then simultaneous equations to get b^2 = 18, hence find a, b, c noting that a>0. The determinant clearly cantt be zero as M would be singular but M^-1 = 1/18 M^T so M is non-singular

Reply 22

infekt

OP

1

Bezza

Determinant is area/volume scaling factor so I don't think it should be negative as you can't have a negative area/volume

its rite ... i got it 2 ... but they asked for the modulus of the det .... unless im forgetting sumthing important

p=3
k=18
a b c ... i dont remember which one was which ... but one was 2root2 root2 and -2root2 ...

i have a graphic calc and i chcek it useing the matrice funsction ...the answers work like a charm ...

Reply 23

qqqwwweee

2

Bezza

Determinant is area/volume scaling factor so I don't think it should be negative as you can't have a negative area/volume

how about the determinant of -1I where I is the identity matrix?

Reply 24

A2 student

What answers you got for the first question?

Reply 25

infekt

OP

1

A2 student

What answers you got for the first question?

remind me wat it was ?

Reply 26

Checkey

Bezza

Determinant is area/volume scaling factor so I don't think it should be negative as you can't have a negative area/volume

Is it like Integration where you have a given area that is under the x-axis, hence when you calculate this you need to ignore the -ve sign and take the number value as the actual area?

Reply 27

qqqwwweee

2

infekt

its rite ... i got it 2 ... but they asked for the modulus of the det .... unless im forgetting sumthing important

p=3
k=18
a b c ... i dont remember which one was which ... but one was 2root2 root2 and -2root2 ...

i have a graphic calc and i chcek it useing the matrice funsction ...the answers work like a charm ...

2root2, -root2 and -2root2

Reply 28

infekt

OP

1

Checkey

Is it like Integration where you have a given area that is under the x-axis, hence when you calculate this you need to ignore the -ve sign and take the number value as the actual area?