Three dimensional geometry

Question

Using Vectors ,prove that the points ( 2, -1 , 3 ) , ( 3, -5 , 1 ) and ( -1 , 11 , 9 ) are collinear.

Answer 1

for all these points to be collinear, they should lie in the same straight line

that is should have same slopes

slope=y2-y1/ x2-x1

slope1 = -5-(-1)/3-2 = -4

slope2= 11-(-5)/ -1-3 = -4

slpoe3= 11-(-1)/ -1-2= -4

 all of them have the same slopes

Therefore they are collinear

thank u

Comments

Its normal method , i have said using vectors