anonymous one year ago Need help with five Algebra 2 questions! Please help me. I'm never able to get help on this website hardly ever.

1. misty1212

HI!!

2. misty1212

any particular question?

3. misty1212

??

4. anonymous

Yes! @misty1212

5. misty1212

best to post a specific question

6. anonymous

let me pull them up!

7. anonymous

Okay my first question is this: What is the graph of the absolute value equation? y = /x/ -9

8. misty1212

do you know what $$y=|x|$$ looks like? that is the basic starting point

9. anonymous

Not really. I've been having a lot of trouble with graphing :(

10. misty1212

it looks like a V |dw:1441118922280:dw|

11. misty1212

to the right of zero it is the line $$y=x$$ to the left it is $$y=-x$$

12. anonymous

Okay I thought so. Can the V's placement move up and down on the graph?

13. misty1212

when you subtract 9 outside, it moves it down 9 units

14. anonymous

Thats what I was about to draw.

15. misty1212

and output is 9 less than $$y=|x|$$

16. misty1212

|dw:1441119016232:dw|

17. anonymous

Okay so when you have y = /x/ will it always look like a V?

18. misty1212

lol yeah it never changes

19. anonymous

And then the number at the end of the equation is where you place it.

20. anonymous

Sorry... Math is not my strongest subject.

21. misty1212

no problem

22. misty1212

if it was say $$y=|x|+2$$ it would be up 2 units

23. anonymous

Do you have time to help me with a few more?

24. misty1212

sure

25. anonymous

Thank you so much!

26. anonymous

What is the graph of the absolute value equation? y = /x+4/

27. misty1212

ok this one is a bit different because FIRST you add 4 THEN take the absolute value

28. misty1212

that shifts the V 4 units to the LEFT`

29. misty1212

|dw:1441119337575:dw|

30. misty1212

don't be confused by going to the left think of it this way the smallest the absolute value can be is zero, so if $$x=-4$$ then $$y=|-4+4|=|0|=0$$

31. anonymous

And its positive right so wouldn't it be to the right?

32. anonymous

Oh! Your reply came in late so I didn't see it! I got it!

33. misty1212

no for the reason i wrote above don't forget the order in which you do things here first add 4, then take the absolute value if $$x=4$$ then $$y=|4+4|=8$$ not 0

34. anonymous

Yes, I understand. I didn't see what you said before I replied.

35. misty1212

it is more general than just for the absolute value compared to $$y=f(x)$$ the graph of $$(y=f(x+4)$$ would be shifted to the LEFT 4

36. anonymous

Okay! I got it :) So the graph would have the v shifted to the left 4

37. misty1212

yes

38. anonymous

Awesome. You are so much help!

39. misty1212

$\color\magenta\heartsuit$

40. anonymous

:) cute!

41. misty1212

quick quiz how would $y=|x+2|-3$ be shifted?

42. anonymous

okay one second

43. anonymous

y = /x+2/ -3 = /0/ -3

44. misty1212

your answer should be left or right so many units, up or down so many units

45. anonymous

Wait... I don't think I'm doing it right

46. anonymous

|dw:1441119892914:dw|

47. misty1212

$\huge y=|x\overbrace{+2}^{\text{left 2}}|\overbrace{-3}^{\text{down 3}}$

48. anonymous

okay let me graph it

49. anonymous

|dw:1441120014777:dw|

50. misty1212

pretty good

51. misty1212

a bit off since it does not go through $$(0,0)$$

52. anonymous

We just learned these in class today

53. anonymous

Yeah it's hard to draw it on here

54. misty1212

|dw:1441120134731:dw|

55. misty1212

close enough

56. anonymous

I have two more if you don't mind.

57. anonymous

I want to try them first and then could you check my answers?

58. misty1212

$\huge y=|x\overbrace{-4}^{\text{ right 4}}|\overbrace{+2}^{\text{up 2}}$

59. misty1212

sure

60. anonymous

What is the graph of the absolute value equation? y = /x+3/ -4

61. misty1212

ok pretty close to the last one we did

62. anonymous

Yes.

63. anonymous

|dw:1441120404739:dw|

64. misty1212

excellent

65. anonymous

|dw:1441120491775:dw|

66. anonymous

More like this though

67. anonymous

Okay the next one has a fraction in it.

68. misty1212

i hate fractions

69. anonymous

What is the absolute value of the equation? y = 1/2 /x/

70. anonymous

Me too

71. misty1212

it can't really ask "what is the absolute value" right? maybe graph it ?

72. anonymous

lol! I left that out! it is graphing

73. misty1212

yeah that looks the the original V except it is wider

74. anonymous

You're graphing -1/2 /x/

75. misty1212

|dw:1441120715407:dw|

76. anonymous

|dw:1441120740635:dw|

77. misty1212

oh is it $y=-\frac{1}{2}|x|$?

78. anonymous

Yes Ma'am.

79. anonymous

So wouldn't it be |dw:1441120824712:dw| ?

80. misty1212

then your are right (ma'am, lol)

81. anonymous

:)

82. anonymous

Okay there's a bonus question on my homework that has a graph like this: |dw:1441120904317:dw|

83. misty1212

where does it sit ?|dw:1441120941672:dw|

84. anonymous

The choices that they give you are: y = 7/x+8/-4 y =-7/x-8/+4 y =-7/x+8/-4

85. anonymous

And y = -7/x-8/-4

86. anonymous

That's what it looks like?

87. misty1212

no that was wrong $$(-8,-4)$$

88. anonymous

Yes.

89. anonymous

(-8, -4)

90. misty1212

so it is going to look like $y=a|x+8|-8$

91. misty1212

and since it opens down $$a$$ is a negative number

92. anonymous

I think it's C

93. misty1212

so probably C ( it is almost always C)

94. anonymous

When in doubt Charlie out! (Thats what my mom says)

95. misty1212

96. anonymous

Okay I finished! Let's see what I got!

97. misty1212

lol yeah let's C

98. anonymous

99. misty1212

yay!!

100. anonymous

Thank you sooooooo much!

101. misty1212

$\huge \color\magenta\heartsuit$

102. anonymous

<3