Answer
Distance between points $(1,-1) $and $(2,-2)$ is-
$\sqrt 2$ OR $1.414$ unit
Work Step by Step
Distance 'd' between two points $(x_{1},y_{1}) $ and $(x_{2},y_{2})$ is given by-
d = $\sqrt{(x_{1} - x_{2})^{2} + (y_{1} - y_{2})^{2}} $
Therefore, distance '$d$' between points $(1,-1) $and $(2,-2)$ will be -
d = $\sqrt{(1 - 2)^{2} + [-1 - (-2)]^{2}} $
i.e. d = $\sqrt{(-1)^{2} + (-1 +2)^{2}} $
i.e. d = $\sqrt{(-1)^{2} + (1 )^{2}} $
i.e. d = $\sqrt{1 + 1} $ = $\sqrt{2} $ = $1.414$ unit
