Is K a variable, an equation, a constant, or a formula?

Since k is constant (the same for every point), we can find k when given any point by dividing the y-coordinate by the x-coordinate. For example, if y varies directly as x, and y = 6 when x = 2, the constant of variation is k = = 3. Thus, the equation describing this direct variation is y = 3x.

Step-by-step explanation:

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value