D is the midpoint of line segment AB. The co-ordinates of A and D are (2, 4) and (-1, 3), respectively. The co-ordinates of B are:

Question

Question

This question was previously asked in

RRB ALP Electrician 22 Jan 2019 Official Paper (Shift 1)

Answer 1

Given:

A = (2, 4) and D = (-1, 3)

Formula Used:

If A = (a, b) and B = (c, d) and D is midpoint of line AB

D = (x, y)

⇒ x = (a + c)/2 and y = (b + d)/2

Calculation:

Let, the co-ordinates of B be (x, y)

According to the question,

(2 + x)/2 = - 1

⇒ 2 + x = - 2

⇒ x = - 4

Also,

(4 + y)/2 = 3

⇒ 4 + y = 6

⇒ y = 2

∴ The co-ordinates of B = (-4, 2)