Answer:
The function is expressed by answer A
Step-by-step explanation:
A function is a mathematical expression in which, for an independent variable , usually called x, we obtain one and only one value after applying the function, usually known as the dependent variable y.
D is not a function as we do not have two corresponding values or coordinate pairs. We only have a list of numbers
In C, B and A we have pairs of coordinate values expressed as (x,y) the independent and dependent variable.
In expression B, we see that the for the value of x=3 in ponts 1 (3.-3) and (3.-9) , the value 3 has two resulting values of y , -3 and -9, so this coordinates do not represent a function.
In option C, occurs something similar in this case with x =9. x=9 has two values in y : y=-6 and y= 2 so these points do not define a function
In A each x value (3.9.0) has a unique avlue of y (-3,-6,-9) so this is a function.
