Question

1.for what value of k the points A(1,5),B(K,1) and C(4,11) are collinear?????

Answer 1

let A B C be three vertices then x1=5,x2=k x3=4 y1=5 y2=1, y3=11.

substitute the value in the following eqn

area of triangle=0  (since abc are collinear)

1/2x1(y2-y3)+x2(y3-y1)+x3(y2-y2)=0

k=-1