I am doing some functions review but I forget how to determin if it is a relation when given an equation
help me please!!

y=-3x +5

y=square root of (3x - 1)

Don't quite understand what you want here...

the relation is a function if when graphed it passes the vertical line test aka no two points have the same x value

An equation represents a function if for any x in the function's domain there is preciely one value of y that emerges. If there is more than 1 possible value of y for any x , then the equation is not a function.

Example: consider the equation y=2x. The domain for x is - \infty < x < + \infty. For any x, there is only one value of y that comes out of the equation. For example y(2) = 4, y(-10) = -20, etc. Therefore y= 2x is a function.

Another example: consider y = \sqrt x . Here x is in the domain 0 \le x < \infty . For x equals zero there is one value of y: zero. But for any positive x there are two values of y, since the square root of a positive number number is either plus or minus. For example, \sqrt 4 = \pm 2. Hence y= \sqrt x is not a function.

Hope this helps.

You mean that functions are the equations having an inverse, that is, are one one? Ok, but I thought that all equations could be represented as functions, but some of which had inverse, and others don't. K, thanks for the specification ebaines.

You mean that functions are the equations having an inverse, that is, are one one? .

Not quite. Consider the equation f(x)= sin(x). This is defintely a fuction since for any value of x there is precisely one value of f(x). Its inverse is g(x) = arcsin(x), which is not a function, as for any value of x there are an infinite number of values for g(x), for example arcsin(0) = 0, pi, 2*pi, 3*pi, etc.

Oh, OK, thanks then, your really a help ebaines. Btw, my school is ebene, having the same pronunciation as your username, tee hee!