Transformations

Jesus1968 · 2018-06-20 14:50:10

I need help of these problems. I got them all wrong. Anyone please help by showing how to work them step by step please.

17. What is the image of triangle PTJ (1, -0), (11, -11), and (7, 7) after a dilation of -7?

18. The translation of triangle BPU (-36, 20), (28, 16), and (8, 12) after a dilation is (9, -5), (-7, -4), and (-2, -3). What is the dilation?

19. The translation of triangle GEP (-4, 10), (-9, -3), and (-6, 6) after a dilation is (-28, 70), (-63, -21), and (-42, 42). What is the dilation?

20. The translation of triangle KTS (6, -36), (-60, 72), and (-54, -36) after a dilation is (1, -6), (-10, 12), and (-9, -6). What is the dilation?

Bob · 2018-06-23 20:57:03

Hi Jesus1968,

These are all centred on the origin so look at any coordinate before and after the dilation using

After = before Times dilation

E.g.

Q18

9 = -36 x d. so d = -1/4

Bob

Ps. A translation is a different thing ... the general term is transformation.

Jesus1968 · 2018-06-24 12:24:58

I am still a bit confused, well then will #17 will be -7=-11 x d, so d=77

Jesus1968 · 2018-06-24 12:30:20

I think I may have looked at this one wrong. #17 will be -7 = -1 x d, so d=1

Bob · 2018-06-25 01:21:52

hi Jesus1968

You seem to be getting very confused. Q17 gives you the dilation and asks for the new coordinates.

Just multiply the old ones by -7 to get six new coordinates (x,y) three times.

Bob

Jesus1968 · 2018-06-25 05:12:00

Ok, I submitted it and got #17 wrong, but got #18 and 19 correct.

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