Determine whether the relation represents y as a function of x.
1.) x^2+y^2=9
2.) 2xy=1

1 is not a function

2 is a function because you can write it (AS) f(x)=1/(2x).

Step-by-step explanation:

1) x^2+y^2=9 is a circle with center (0,0) and radius 3.

To get this all I did was compare to (x-h)^2+(y-k)^2=r^2 where (h,k) is the center and r is the radius.

A circle is not a function.

You can solve solve for and see that you will get two values for y which is no go for a function.

Let's do that:

Subtract x^2 on both sides:

Square root both sides:

.

2) 2xy=1

Divide both sides by 2x:

y=1/(2x).

This is a function only one y there.

answer: 5 17/33 % (to the tenth)

step-by-step explanation:

he guessed: 34.5 pounds

actual weight is 32.7

there for he is off:

34.5 -32.7 = 1.8

32.7 is the 100%

1.8 represents %? of 32.7

therefore:

32.7   - 100%

1.8     -     x%

x= 1.8*100%/32.7% = 18*100%/327%

x=1800%/327%   = (5 165/327)%

to the tenth:

5 17/33 %