we know that
In a function, for an input there is only one output
so
the image of input and output is not a function , because
for input 0 we have two output (2 and 3)
the table of x and y is a function
the set (-1,5), (2,5),(3,5),(8,5) ------> is a function
the other image of input and output is a function
the circle is not a function
the inclinated line is a function
the vertical line is not a function
the first graph of point is a function
the other graph of points is not a function
Remember
for a value of x ---------> is only one value of y
example
we have the point (3,-1) and (3,-3)
for one value of x (x=3) there is two values of y (-1 and -3)
therefore
is not a function