Question

The point P lies on line A, B where A = (2, 4, 5} and B = (1, 2, 3). If z co-ordinate of point P is 3, the its y co-ordinate is ______.

विकल्प

• 3

• -3

• 2

• -2

Answer 1

The point P lies on line A, B where A = (2, 4, 5} and B = (1, 2, 3). If z co-ordinate of point P is 3, the its y co-ordinate is 2.

Explanation:

We have. A ≡ (2, 4, S)and B ≡ (1, 2, 3)

Equation of AB is,

`(x - 2)/(1 - 2) = (y - 4)/(2 - 4) = (z - 5)/(3 - 5) = lambda`

`(x - 2)/(-1) = (y - 4)/(- 2) = (z - 5)/(- 2) = lambda`

Putting z = 3, we get

`lambda = (3 - 5)/(- 2) = 1`

`therefore (y - 4)/(- 2)` = 1

⇒ y - 4 = - 2

y = 2