KCET 2018 Math Solved Paper

Given line

x

1

=

y−1

2

=

z−2

3

→ (1)
Point P(1, 6, 3) and reflection Q.Let ‌

x

1

=‌

y−1

2

=‌

z−2

3

=λ
and point R on line. So, coordinates of R is
(λ,1+2λ,2+3λ)
Direction ratios of line is (1, 2, 3).
Since PR is perpendicular to the given line. Then, direction ratios of

−

PR

=(λ−1,2λ−5,3λ−1)
So, λ−1+2(2λ−5)+3(3λ−1)=0
⇒14λ=14⇒λ=1
Therefore, R(1, 3, 5) and Q(1, 0, 7)