Question

Point A(3,-2) B(1,-1) and C(k, 4) are collinear k=? ​

Answer 1

-3/2

here it is. Here if pts. are collinear then their slope will be same.

Answer 2

Answer:

k=-9

Step-by-step explanation:

for the points to be collinear area of triangle is 0

x1 = 3

x2 = 1

x3 = k

y1 = -2

y2= -1

y3= 4

$\frac{1}{2} |x1(y2 - y3) + x3(y3 - y1) + x3(y1 - y2)| = 0 \\ x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2) = 0 \\ 3( - 1 - 4) + 1(4 + 2) + k( - 2 + 1) = 0 \\ 3( - 5) + 1 (6) + k( - 1) = 0 \\ - 15 + 6 - k = 0 \\ - 9 - k = 0 \\ - k = 9 \\ k = - 9$