Question

The point which lies
the line y = 2x​

Answer 1

Equation of the line is y = 2x

(a) Point A lies on the line y = 2x so it satisfies the equation of the line.

y=2(−2)=−4

Hence y coordinate of point A is -4.

(b) To verify whether a circle of radius 5 centred at point A(-2, -4) passes through the point B(5, 5) it is enough to show that the distance between point A and B is 5.

AB=

(5+2)

2

+(5+4)

2

=

49+81

=

130



=5

Hence a circle of radius 5 centred at point A(-2, -4) does not pass through the point B(5, 5).

(c) Let (x

1

,y

1

) be the coordinates of centre C on line.

Therefore it satisfies the equation of line a y = 2x

∴y

1

=2x

1

Also the distane between point B and C is radius that is 5.

So BC

2

=25

(x

1

−5)

2

+(y

1

−5)

2

=25

(x

1

−5)

2

+(2x

1

−5)

2

=25 [∵y

1

=2x

1

]

5x

1

2

−30x

1

+25=0

x

1

2

−6x

1

+5=0

(x

1

−5)(x

1

−1)=0

x

1

=5 or 1

y

1

=2x

1

=2(5)=10

y

1

=2x

1

=2(1)=2

The coordinates of point of C are (5, 10) or (1, 2).

Answer 2

4.2/5.11 sangharsh 1234.age .476