Use scalar multiplication to determine the coordinates of the vertices of the dilated figure. Then, graph the pre-image and the image of the same coordinate grid.

Quadrilateral WXYZ with vertex matrix [-1 5 5 -2]
[2 5 3 -5] with a scale factor 3.

Question

Use scalar multiplication to determine the coordinates of the vertices of the dilated figure. Then, graph the pre-image and the image of the same  coordinate grid. 

Quadrilateral WXYZ with vertex matrix [-1 5 5 -2]
                                                            [2 5  3  -5] with a scale factor 3.

jhannybean · Answer

@amistre64

sammietaygreen · Answer

^thank you!! I need help I just don't get it

amistre64 · Answer

just multiply it all by 3

sammietaygreen · Answer

I did that but when I plotted it, it looked nothing like the options?

amistre64 · Answer

i cant see what you did from here ...

jhannybean · Answer

Oh so this is how a Jacobian works too,... sort of. Right @amistre64 ? Haha. That's what I initially thought this was.

amistre64 · Answer

well, its not a jacobian (thats a cross product type thing)

this is just scaling a vector really.

amistre64 · Answer

the matrix is made of ordered pairs, and scaling each ordered pair by 3 results in a new scaled pair ...

sammietaygreen · Answer

3 15 15 -6
6 15 9 -12

sammietaygreen · Answer

let me show you guys the answer choices.

sammietaygreen · Answer

because I have no idea what I'm doing wrong lol

amistre64 · Answer

[-1 5 5 -2] 
[2 5 3 -5]

[-1(3) 5(3) 5(3) -2(3)] 
[2(3) 5(3) 3(3) -5(3)]

is NOT what youve worked.

amistre64 · Answer

you got 2 values off

sammietaygreen · Answer

OHH then do I just plot them??

sammietaygreen · Answer

like how do I plot them

amistre64 · Answer

how do you read an ordered pair?  (x,y)

sammietaygreen · Answer

like (-3, 6)?

amistre64 · Answer

[ [-1(3), 5(3)]   [5(3), -2(3)] ]

[ [  2(3), 5(3)]  [3(3), -5(3)] ]

jhannybean · Answer

I thought ordered pairs matched vertically,... hm.

sammietaygreen · Answer

yeah, same here^^