The graph of \(y = x^2 + x − 6 \) crosses the \(x\)-axis at \(x = -3\) and \(x = 2\). The coefficient of \(x^2\) is positive, so the graph will be a positive U-shaped curve with a turning point ...

The graph of \(y = x^2 + x − 6 \) crosses the \(x\)-axis at \(x = -3\) and \(x = 2\). The coefficient of \(x^2\) is positive, so the graph will be a positive U-shaped curve with a turning point ...

Since the 1970s, they’ve known how to find shortest paths essentially as fast as theoretically possible, assuming all weights are positive numbers. But on some graphs weights can be negative — ...