The function doesn't have inverse because it doesn't pass the horizontal line test. This test tells us that a function has an inverse function<em> if and only if</em> there is no any horizontal line that intersects the graph of at more than one point. As you can see, from the graph of f (the red one), if you draw an horizontal line that passes through then this line will touch the graph of f at three points, so the horizontal line test is not satisfied here. If you see the graph of g, this doesn't represent a function because there is at least one vertical line that touches the graph at more than one point, so this relation is not a function.
Explanation: Area of a triangle= 1/2base x height Plug in information 30=1/2 x 4 x h Solve 1/2 x 4 = 2 30= 2 x h Divide both side by two 30/2=2 x h/2 Solve: 15= h
