Concyclic points⭕

Geometry Level 3

A circle is constructed using three concyclic points (8,6) , (7,7) , (4,8) .

The circle cuts the Y-axis at (0,y) and cuts the X-axis at (x,0) and also cuts origin.

Find the value of x+y .


This is an original problem and belongs to my set Raju bhai's creations

21 14 28 7

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Vignesh Rao
Nov 12, 2017

Since the circle passes through the origin it is of the form: x 2 + y 2 + 2 g x + 2 f y = 0 x^2 +y^2 +2gx + 2fy =0

The circle passes through the points ( 8 , 6 ) , ( 7 , 7 ) , ( 4 , 8 ) (8,6) , (7,7) , (4,8) . Substituting for x and y in the above equation and solving for g g and f f gives us

g = 4 f = 3 g = -4 \ \ \ \ \ \ \ \ \ \ \ \ f = -3

Therefore, the equation of the required circle is x 2 + y 2 8 x 6 y = 0 x^2 + y^2 -8x - 6y =0 .

For x = 0 x = 0 : y = 0 or y = 6 y = 0 \ \text{or} \ y = 6

For y = 0 y = 0 : x = 0 or x = 8 x = 0 \ \text{or} \ x = 8

Therefore, the point of intersection with Y axis is ( 0 , 6 ) (0,6) and that with X axis is ( 0 , 8 ) (0,8)

Hence, the value of x + y = 8 + 6 = 14 x + y = 8 + 6 = 14

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...