Does the equation y = +-5X represent a function?

Question

Does the equation y = +-5X represent a function?

Answer 1

Hi Garrett;

y = +-5X

I assume this equation was originally...

y²=(5x)²

We must remember that, when squared, negative 5x (- 5x) will produce the same result as positive 5x (+ 5x).

The definition of a function is that a vertical line can only pass through this line once.  Because of the y², each value of x will be represented twice on the y-axis.  Henceforth, the vertical line will pass through this line twice.

Let's try x=5

y²=(5x)²

y²=[(5)(5)]²

y²=625

y=+/-25

(5,+25)

(5,-25)

THIS IS NOT A FUNCTION.

 

 

Answer 2

+ to Vivian.

 

Y = +/- 5X

 

example, X = 1, then Y equals EITHER +5 or -5, violating the Vertical Line test - Not a function.

Answer 3

 Yes itis because:

 

   Y = ± 5 X

 

   Each Value of X , there is only one value of Y

 

      (- 1, - 5)

     

      ( 1,  5 )

 

      ( -2 , -10) 

 

      ( 2, 10)

 

     It passes the vertical test for function.