Question

show that the points ( 1,2 ), ( 2,1 ), ( -2,5 ) lie on the same line i.e,
collinear

Answer 1

A=(1,2) B=(2,1) C=(-2,5)
AB = √[(2-1)^2 + (1-2)^2] =√(1+1) =√2
BC= √[(-2-2)^2+(5-1)^2]=√(16+16) =√32 =4√2
AC = √[(-2-1)^2+(5-2)^2]=√(9+9) =√18=3√2
BC= AB+AC
therefore the points are collinear

Answer 2

Answer:

+3

Step-by-step explanation:

given a to be distance=√10

√x1^2+y1^2=√10

√1^2+x^2=√10

1+x^2=10

x^2=10-1

x^2=9

x=√9

x=3