Answer:
Graph 2: the linear function.
Step-by-step explanation:
A function is invertible if its bijective: injective and surjective at the same time. But, graphically exist the horizontal line test to know if the function is injective, i.e., one to one: one element of the domain has a unique element in the image set.
So, in this case, the only function that can be cut once by a imaginary horizontal line is graph number 2. If we draw a horizontal line in other options, it will cut them in more than one point, meaning that they are not injective, therefore, not invertible.
