Question

Help??? will give medal and fan for right answers!! pls answer both!! attached below!!

Answer 1

y = kx where k is a constant number is the formula for a direct linear variation IIRC

Answer 2

So for number 1, can you pick out which one is/isn't the direct linear variation?

Answer 3

for example. y = 3x y = 2x y = 6x etc. are all direct linear variations.

y=x^2
y=x-1 aren't

Answer 4

y=x-1? I dont think that was one of the answers

Answer 5

It isn't I'm trying to teach you what is and isn't a direct linear variation.

Answer 6

Do you want to start solving the first part?

Answer 7

Sure

Answer 8

Which one do you think is or isn't a direct linear variation?

Answer 9

I think b isnt

Answer 10

B is the only one that matches this format
y = [some number] * x.

Answer 11

A/C/D are all formatted differently, using subtraction etc.
You need a number multiplied by x. fractions are still numbers

Answer 12

i was right???? o.O

Answer 13

B is the answer

Answer 14

omg I can't read

Answer 15

good job o(〃＾▽＾〃)o

Answer 16

thank you for your help ^o^

Answer 17

woah woah we're not even done

Answer 18

for the second part, 2 of the choices are DLV and 2 aren't.

Answer 19

Oh? I forgot about the second one

Answer 20

So plug in y = 12 and x = 3 into A/B as they're the direct linear variations

Answer 21

okay

Answer 22

Any progress?

Answer 23

Is it A?

Answer 24

yup. 12 = 4*3. gj gj gj

Answer 25

thank youuuu! ^o^ @bibby

Answer 26

np np
♥(✿◠‿◠) ♥

Answer 27

Would you mind helping me with a few more? ^^ @bibby just two or three ^^

Answer 28

yeah, if I know the math. you can post it here or in another question

Answer 29

@bibby thank you!

Answer 30

again, we want the equation to look like y = k (some number) * x^2

Answer 31

mhm! ^^

Answer 32

I'm not sure how to demonstrate the working out of this, but D is the quadratic variation.

y = 3x^2. I kinda just did it in my head

Answer 33

D is the answer o:

Answer 34

D is the first answer, for the second you just plug in the numbers

Answer 35

Is the second one c?

Answer 36

plug in the numbers, you get
\[48=\frac{ 1 }{ 24 }*2^2 = \frac{ 4 }{ 24 }\]not exactly.

Answer 37

Wait? D?

Answer 38

we're looking for some number that fits this description:

48 = ? * 2^2
48 = ? * 4

Answer 39

sssssssso cloossssse

Answer 40

I dunno :c B?

Answer 41

You shouldn't be guessing lol. B is the only one that makes sense.

B: y = 12x^2
y=48
x^2= 2*2 = 4
48 .= 4*12 = true

Answer 42

I was right though! ahah ^^ I only have two more, sorry to be taking all your time, but I really appreciate it!

Answer 43

My time, lol. it's cool, don't worry

Answer 44

an inverse variation is formatted like \[y=\frac{ k }{ x }\]

Answer 45

for the first one, try to derive the formula.

f(x) = 30
x = 2\[30 = \frac{ ? }{ 2 }\]

what is k?

Answer 46

60?w haa?

Answer 47

exactly. so for 1a, the inverse variation looks like:\[y=\frac{ 60 }{ x }\]
does that apply to everything in 1a?

Answer 48

Yeah- because 30= 60/2 ?????

Answer 49

you have to do it to all the x's on the table, but yeah, it works

Answer 50

yea

Answer 51

for part 2, which one is the inverse variation?

Answer 52

wait what? i dunno which one was part 1

Answer 53

A

Answer 54

60/2=30
60/3=20
60/4=15
60/5=12

Answer 55

Oh! okay ^^

Answer 56

and for part two

Answer 57

for part 2, look for the inverse variation. remember they're in this format:
\[\huge y= \frac{ k }{ x }\]

Answer 58

yep!

Answer 59

that's not an answer choice

Answer 60

your other choice is plugging in y and x till you get an equivalence

Answer 61

yes, I figure

Answer 62

So any ideas?

Answer 63

8= k/2

Answer 64

yep

Answer 65

high five brotha

Answer 66

and k is 16? haha

Answer 67

woah woah

Answer 68

??

Answer 69

whoops. the equation is y=16/x
k=16

Answer 70

Ah, mhm ^^

Answer 71

I think it's B

Answer 72

yus

Answer 73

yeaayyy :D

Answer 74

>:D

Answer 75

I have one more ^^

Answer 76

is we done yet

Answer 77

lay it on me brotha

Answer 78

if you don't remember graph transformations (like me)
You can use the x/y intercepts as a guideline.

What is the x and y intercept of that equation?

Answer 79

Not sure?/?

Answer 80

y-intercept = set x = to 0
x-intercept = set y = to 0

Answer 81

all you really need is the x intercept I think

Answer 82

yeah so solve for g right

Answer 83

mhm,

0 = x-3

Answer 84

x = 3, the x intercept is 3. Also notice how there's no negative so the graph is a straight v

Answer 85

http://www.wolframalpha.com/input/?i=abs%28x-3%29

Answer 86

Oh! It's A! thank you!

Answer 87

np, np