Question

Find distance between point A(–1, 1) and point B(5, –7):

Solution: Suppose A(x₁, y₁) and B(x₂, y₂)

x₁ = –1, y₁ = 1 and x₂ = 5, y₂ = –7

Using distance formula,

d(A, B) = `sqrt((x_2 - x_1)^2 + (y_2 - y_1)^2`

∴ d(A, B) = `sqrt(square +[(-7) + square]^2`

∴ d(A, B) = `sqrt(square)`

∴ d(A, B) = `square`

Answer 1

Suppose A(x₁, y₁) and B(x₂, y₂)

x₁ = –1, y₁ = 1 and x₂ = 5, y₂ = – 7

Using distance formula,

d(A, B) = `sqrt((x_2 - x_1)^2 + (y_2 - y_1)^2`

∴ d(A, B) = \[\sqrt{\boxed{[5 - (-1)]^2} + [(-7) + \boxed{-1}]^2}\]

∴ d(A, B) = `sqrt(6^2 + (-8)^2`

∴ d(A, B) = `sqrt(36 + 64)`

∴ d(A, B) = \[\sqrt{\boxed{100}}\]

∴ d(A, B) = \[\boxed{10 \phantom{.}\text{units}}\]