The graph of shows that the only interval where is between somewhere near y=2.5 and y=3. It's obvious that the two functions and are equal when y=3. The only way I can see to show that when y>3 is to use calculus (which I guess isn't allowed in the pre-calculus forum). To find the other point where the two functions are equal is definitely tricky – there is no elementary way to find the point where the graph crosses the axis near y=2.5.