Graph the function and use the horizontal line test to determine whether the inverse is a function. f(x) = 2x3 a. yes b. no

Check the picture below.

bear  in mind that, to check in a graph if an expression is a function, all you need is the vertical line test(the red lines) only.

now, if you're doing a horizontal line test(the green lines), and the expression passes both, then the expression is not just a function, is a one-to-one function, and therefore, it has an inverse function.

now, notice the picture on this one, the lines vertical and horizontal ones, touch the graph only once as they go by, therefore, it passes both.