Answer: The required distance between the points between A(1, 1) and B(7, −7) is 10 units.
Step-by-step explanation: We are given to explain the distance formula. Also, to calculate the distance between A(1, 1) and B(7, −7).
<em><u>Distance formula :</u></em> The distance between any two two points with co-ordinates (a, b) and (c, d) is given by
![D=\sqrt{(c-a)^2+(d-b)^2}.](https://tex.z-dn.net/?f=D%3D%5Csqrt%7B%28c-a%29%5E2%2B%28d-b%29%5E2%7D.)
Therefore, the distance between the points A(1, 1) and B(7, −7) is given by
![D\\\\=\sqrt{(7-1)^2+(-7-1)^2}\\\\=\sqrt{36+64}\\\\=\sqrt{100}\\\\=10.](https://tex.z-dn.net/?f=D%5C%5C%5C%5C%3D%5Csqrt%7B%287-1%29%5E2%2B%28-7-1%29%5E2%7D%5C%5C%5C%5C%3D%5Csqrt%7B36%2B64%7D%5C%5C%5C%5C%3D%5Csqrt%7B100%7D%5C%5C%5C%5C%3D10.)
Thus, the required distance between the points between A(1, 1) and B(7, −7) is 10 units.