Question

Which does not represent y as a function of x?

A. x=y^2+2
B. y+x^2+2
C. x=y+8
D. y=-x+8

I've been out of math for 3 years. Please help! :)

Answer 1

anyone??

Answer 2

did you mean to write B without an equal sign in it? If so, then I believe B is not a function

Answer 3

I mean y as a function of x

Answer 4

oh no B is y=x^2+2
sorry

Answer 5

could you tell me how you figured that out please??

Answer 6

my answer is wrong. Let me look at it again. One moment

Answer 7

kay

Answer 8

A. x=y^2+2
B. y=x^2+2
C. x=y+8 ------> can be written as y=x-8 (brought 8 over to the other side)
D. y=-x+8

ok so now we have

A. x=y^2+2
B. y=x^2+2
C. y=x-8
D. y=-x+8

they're all y as a function of x except for 1

Answer 9

So A. is written "x in terms of y" because here
\[x=y^2+2\]

Answer 10

okay thank you

Answer 11

@radar can explain this better than I can. He should be here momentarily

Answer 12

A. y=sqrt(x-2) or y=-sqrt(x-2)
It depends on whether y is positive or negative

Answer 13

If a value of x results in more than 1 value of y, then it is not a function.

Answer 14

ok that makes sense

Answer 15

Looking at A. x=y^2 +2, then y^2=x-2
then \[y=sqrt{x-\2\}\\]Letting x=6, then\[y=sqrt{\6\-\2\}\=sqrt{\4\}\=\ \+\2\ and \-\2\\]A. is not a function.

Answer 16

Looks like the equation editor is on the blink!

Answer 17

could you guys help with one more problem??

Answer 18

sure post it as a new problem on the left