Question

If vector AB = i+7j-2k and B is point (7,4,4). Find A.

Answer 1

A is point ( 6, -3, 6)

Explanation:

Here in this question, we are concerned with finding the coordinates of point A.

Since we do not know the coordinates of point A, let’s represent them as (x,y,z)

By vector properties; Mathematically ;

AB = (7,4,4) - (x , y, z)

Thus; AB = (7-x)i + (4-y)j + (4-z)k

From the question, we are told that AB is also i + 7j -2k

By comparison;

(7-x)i = i

7-x = 1

x = 7-1

x = 6

(4-y)j = 7j

4-y = 7

4-7 = y

y = -3

and lastly

(4-z)k = -2k

4-z = -2

4 + 2 = z

z = 6

So the coordinates of A are (6, -3, 6)