Question

5. Find the value of x for which the points ( X. -1), (2,1) and (4,5) are collinear.​

Answer 1

Answer:

x= 1

Step-by-step explanation:

if collinear

area formed by 3 points ∆=0

$\frac{1}{2} |x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2)| = 0$

$\frac{1}{2} |x(1 - 5) + 2(5 - - 1) + 4( - 1 - 1)| = 0$

$\frac{1}{2 } | - 4x + 2 \times 6 + 4 \times ( - 2)| =$

$| - 4x + 12 - 8| = 0 \times 2$

$| - 4x + 4| = 0$

$- 4x = - 4$

$x = 1$