Q. 14.2( 11 Votes )
L is variable line such that the algebraic sum of the distances of the points (1, 1), (2, 0) and (0, 2) from the line is equal to zero. The line L will always pass through
A. (1, 1)
B. (2, 1)
C. (1, 2)
D. none of these
Answer :
Let ax + by + c = 0 be the variable line. It is given that the algebraic sum of the distances
of the points (1, 1), (2, 0) and (0, 2) from the line is equal to zero.
∴
⇒ 3a + 3b + 3c = 0
⇒ a + b + c = 0
Substituting c = – a – b in ax + by + c = 0, we get:
ax + by – a – b = 0
⇒ a(x – 1) + b(y – 1) = 0
⇒
This line is of the form L1 + λL2 = 0, which passes through the intersection of L1 = 0 and L2 = 0, i.e. x – 1 = 0 and y – 1 = 0.
⇒ x = 1, y = 1
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