Question

Which of the following sums would be under the radical symbol to find the distance between the points (7, -1) and (-8, -9)?

1²+10²
1+8²
15²+8²

Answer 1

So the distance formula is
`√((x_2-x_1)^2+(y_2-y_1)^2)` . Using this, our equation is
`√((7-(-8))^2+(-1-(-9))^2)` and we can solve for it as such:

`√((7-(-8))^2+(-1-(-9))^2)\\ √(15^2+8^2)`

As we see with this radical, the sum that's under it is 15^2 + 8^2, or the third option.