Which of the following is not a function

The first graph (ellipse) is not a function.

Step-by-step explanation:

Consider the provided graphs.

We need to determine which is not a function.

The vertical line test can be used to determine whether a graph represents a function.

If the vertical line intersect the graph more than one point then the graph is not a function.

Now consider the figure 1.

The first graph intersect the vertical line 2 times.

Therefore, the first graph (ellipse) is not a function.

step-by-step explanation:

f(x)=2x^2 -1 

translation is a function transformation that transform the function in a way of translating. by translating the function its graph is moved  up an down. moving the function f(x) 2 units to the left will be the new function g(x) with the equation: g(x)=f(x+2)=2(x+2)^2 -1