Question

find the value of k if the points A 1, 2 b 3, k and C 5, -4 are collinear


plz anybody send the answer from rd sharma of 10 class ​

Answer 1

you have find the value of k

then if the point a1,2,b3 k

Answer 2

Solution-

1. Find the slope of the line on which the points lie as points are collinear.

Taking points A(1,2) and C(5,-4)

slope= (y2-y1) / (x2-x1) = (-4-2) / (5-1) = -6 / 4 = -3/2

2. Equation of line is y= mx+c, where m is the slope of the line and c is the y-intercept.

so, y=-3/2x + c

now to fine c, use point A(1,2) which lie on the line.

so, 2= (-3/2)x1 + c

2 + 3/2 = c

7/2 = c

3. Now put point B(3,k) to find value of k.

so, k= (-3/2) x 3 + 7/2

k = -9/2 + 7/2

k = -2/2 = -1

Hence answer is k = -1