Which function has an inverse that is also a function

In order for a function to have an inverse that is also a function there are 2 main requirements:

1. The function should be bijective (ie) the function should be one-one ( each element in codomain has not more than 1 pre image in domain) and onto ( Range should be equal to codomain)

2. The inverse function should be defined by a suitable domain and range

Hope this answer helps you..

left 3, up 4

step-by-step explanation:

just count the values of x & y of the vertex of the graph and see how many units in the x and y direction will get you from the f(x) graph to the f(x) graph