Question

Distance between A (2, -1) and (2,a) is 4 units. Find the value of a where a is positive.

Answer 1

Answer:

a = 3

Step-by-step explanation:

Calculate the distance d using the distance formula and equate to 4

d = $\sqrt{(x_{2}-x_{1})^2+(y_{2}-y_{1})^2 }$

with (x₁, y₁ ) = (2, - 1) and (x₂, y₂ ) = (2, a)

d = $\sqrt{(2-2)^2+(a+1)^2}$ = $\sqrt{0+(a+1)^2}$ = $\sqrt{(a+1)^2}$ = a + 1 then

a + 1 = 4 ( subtract 1 from both sides )

a = 3