INSTRUCTOR: Find the distance between the points P1 equals the ordered triple 1, comma, negative 5, comma, 4 and P2 equals the ordered triple, 4, comma, negative 1, comma, negative 1. Let's apply our distance formula, so d equals. And this will be the square root of the sum of the squares of the differences of those components. So in this question, that will be d equals the square root of 4 minus 1 squared. 4 minus 1 quantity squared plus, parentheses, negative 1 minus negative 5, close parentheses, squared. Plus, in parentheses, negative 1 minus 4, close parentheses, squared.

And as I already said, the square root of those sums. 4 minus 1 squared will be 9. Negative 1 minus negative 5 will be 4. So squared, that's 16. So 9 plus 16. Negative 1 minus 4 is negative 5. That squared is 25. So we have the square root of 9 plus 16 plus 25, which is the square root of 50. And since 50 is 25 times 2, square root of 50 is the square root 25 times 2, or 5 square root of 2. And that is the distance between those two points.