Question

How do you find the value of a given the points (8,-5), (a,4) with a distance of
√85

Answer 1

Answer:

The answer is $a=10,6$

Step-by-step explanation:

Concept : Distance between the points A$(x_1,y_1)$ and B $(x_2,y_2)$ is

                                      $\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$

Here  $\sqrt{(a-8)^2+(4+5)^2}=\sqrt{85}$

        Square both sides

        $\Rightarrow (a-8)^2+81=85\\\Rightarrow (a-8)^2=85-81\\\Rightarrow (a-8)^2=4\\\Rightarrow a-8=2,-2\\\Rightarrow a=8+2,8-2\\\Rightarrow a=10,6$