Question

8 Find the points on the X-axis which are at a distance
of 2root5 from the point (7, - 4). How many such points
are there?
CBSE 2011​

Answer 1

Step-by-step explanation:

let the coordinate of the point be (x,0) (since it is on x axis y is 0)

using distance formula

(x-7)^2 + (0- -4)^2 = (2√5)^2

(x-7)^2 + 4^2 = (2√5)^2

(x -7)^2 + 16 = 20

(x - 7)^2 = 4

x - 7 = +_2

this gives

x = 5 or x = 9

so there are two points

(5,0) and (9,0)