Question

From the official "retired" Praxis Test, Math Content Knowledge 0061. I'm usually good at matrices, but I don't understand the notations they use in this question, and I've seen it used in other questions as well: The matrix representation for the linear transformation T:R^3 -> R^3 is A= (can't type the 3x3 matrix, but all zeros except for 1's in 1,2 2,3 and 3,1 ) . If COLUMN vector v=(2 3 4) then T(v) = ??

Answer 1

okay, so is R^3 just a fancy way of saying a 3x3 matrix? Is T(v) just indicating to multiply the 3x3 matrix by the column vector??

Answer 2

T(v) is the image of v under the mapping rule

Answer 3

in otherwords: Av = ??

Answer 4

Sorry it's been 31 years since Linear Algebra in college. please explain what you mean in this context by image and mapping?

Answer 5

a mapping is a rule that takes an element from a domain and assigns to it an element from another set, the range. the element of the range that it is mapped to is called the image.

T is defined to me the matrix A, that is used to map a given vector x onto B

T(x) is the image of x under the application of A

T(x) = b
Ax = b

Answer 6

Yikes, all that to say multiply the matrices? Half of this stupid test is figuring out what the heck they are asking for!!!!

Answer 7

this is just mathical speak that is designed for rigor is all. consider the mapping f, that maps X to Y\[f:X\to Y\] the rule that defines \(f\) is say:
\[f(x)=x^2+2\]since \(Y\) is the image of \(X\) under \(f\), then:\[y=x^2+2\]

Answer 8

yeah :)

Answer 9

Thanks!

Answer 10

Thanks!

Answer 11

i have a secret praxis site if you would like to see it

Answer 12

Satellite73: really??

Answer 13

lol, no soliciting secret gardens on this site please

Answer 14

for PA math content
took the test and then came home and wrote as any questions as i could remember

Answer 15

all the question that i can remember when i get home usually involve: where did the remote go?

Answer 16

lol
i was doing it for a that specific reason, to get the questions

Answer 17

@sbrestein are you taking it in PA?

Answer 18

Taking it in MD. Found a great Henrico County, VA site.
That school district actually tries to help its teachers to become highly qualified

Answer 19

Does PA do the Praxis 2 0061 for HQT or does it have its own test, like CA does?

Answer 20

good because in PA i couldn't find out squat
email me at
satellite73.opentstudy@gmail.com and i will send you the link to the site where i posted questions
it is not linked to from anywhere as they frown upon it, but it is still up somewhere

Answer 21

i am not sure
but if you are taking the math praxis, i can't imagine these problems would hurt you to look at

Answer 22

it is so secret i can't find it
but i know it is up somewhere

Answer 23

ok found it
it has some stuff like this