Question

Describe the change to the parent function. *I don't really get these at all much*

1. y = -3x^2
2. y = 2/5x^2
3. y = x^2 + 3
4. y = x^2 - 2
5. y = (x + 2) ^2
6. y = (x - 4)^2
7. y = 2x^2 + 1
8. y = -x^2 - 5
9. y = 4(x + 2)^2 - 1
10. y = -1/3(x - 1)^2 + 2

Answer 1

My Answers: Choices (reflection over x or y - axis, hz or vt stretch, hz or vt compression, up/down, left, right)

1. reflection over x-axis and vt stretch
2. vt stretch
3. up 3 units
4.down 2 units
5. left 2;
6. right 4;
7. up 1 unit;
8. down 5 units;
9. left 2 units; down 1 unit; vt. compression
10. up 2 units;

Answer 2

@jim_thompson5910 @Loser66 @Directrix @dtan5457 @Luigi0210 @jagr2713 Help me please, I have the answers and I need to make sure if there is anything I need to add to any questions

Answer 3

1. vertical stretch by what factor?

2. vertical stretch by what factor?

3. correct

4. correct

5. correct

6. correct

7. you're missing the vertical stretch

8. you have a reflection going on here

9. vertical stretch by what factor?

10. you forgot about the vertical stretch and horizontal translation

Answer 4

@jim_thompson5910 what do you mean by vt stretch by what factor; #8 is reflection over x -axis; what do you mean by hz translation on #10

Answer 5

example:

parent function is y = x^2

the function turns into y = 9x^2

the vertical stretch is by a factor of 9 (so each point's y coord is multiplied by 9, ie it's 9 times taller in a way)

Answer 6

y = -1/3(x - 1)^2 + 2

has a horizontal translation of 1 to the right (we shift 1 unit to the right)

due to that x-1

Answer 7

so #10 is a vt stretch of -1/3

Answer 8

also, 10 has a reflection (because of the negative 1/3)

Answer 9

reflection over x-axis

Answer 10

I'd say "vertical stretch of 1/3"

not -1/3

you usually say the magnitude of how much you're stretching

Answer 11

so am I good on my answers @jim_thompson5910:

My Answers: Choices (reflection over x or y - axis, hz or vt stretch, hz or vt compression, up/down, left, right)

1. reflection over x-axis and vt stretch of 3
2. vt stretch of 2/5
3. up 3 units
4.down 2 units
5. left 2
6. right 4
7. up 1 unit; vt stretch of 2
8. down 5 units; reflection over x-axis
9. left 2 units; down 1 unit; vt. compression
10. up 2 units; vt stretch of 1/3; shifted 1 unit to the right; reflection over x-axis

Answer 12

everything looks good, but 9 is still missing the amount you're stretching vertically

Answer 13

and because the '4' is larger than 1, you aren't compressing

you're stretching

Answer 14

# 2 and #10 are vertical compressions

Answer 15

I thought we said 2 and 10 were vertical stretches

Answer 16

notice the 2/5 is less than 1

that means we have a compression

it's a dilation and you can refer to it like that if you want

Answer 17

read this article

http://www.regentsprep.org/regents/math/algtrig/atp9/funclesson1.htm

Answer 18

so #9 is vt compression of 4

Answer 19

focus on the "Stretch or Compress Functions" section

Answer 20

no the 4 outside is larger than 1

Answer 21

y = a(x-h)^2 + k

if a > 1 or a < -1, then we have vertical stretching

if -1 < a < 1, then we have vertical compression

Answer 22

so #9 is vt stretch of 4 then

Answer 23

yes

Answer 24

so is all of my answers in good top shape now lol

Answer 25

yes they look good

Answer 26

@jim_thompson5910 I was wondering how #1 isn't a vertical compression since its less than 1?

Answer 27

y = a(x-h)^2 + k

if a > 1 or a < -1, then we have vertical stretching

if -1 < a < 1, then we have vertical compression

Answer 28

a = -3 fits the first description: "if a > 1 or a < -1, then we have vertical stretching"

Answer 29

read this page

http://www.regentsprep.org/regents/math/algtrig/atp9/funclesson1.htm

read everything on it, but pay special attention to the "Stretch or Compress Functions" section