Question

The slope of aline joining P(6,k) and Q(1 - 3k, 3) is `1/2` Find
(i) k.
(ii) mid-point of PQ, using the value of 'k' found in (i). 

Answer 1

(i) Slope of PQ = `(3 - k)/(1 - 3k - 6)`

`=> 1/2 = (3 - k)/(-3k - 5)`

`=>` -3k - 5 = 2(3 - k)

`=>` -3k - 5 = 6 - 2k

`=>` k = -11

(ii) Substituting in P and Q, we get

P(6, k) = P(6, 11) and Q(1 - 3k,3) = Q(34, 3)

Mid point of PQ = `((6 + 34)/2, (-11 + 3)/2) = (40/2, (-8)/2) = (20, -4)`