Straight Line Question 137

Question: If (- 2, 6) is the image of the point (4, 2) with respect to line L = 0, then L = [EAMCET 2002]

Options:

A)3x ? 2y + 5

B)3x ? 2y + 10

C)2x + 3y ? 5

D)6x ? 4y ? 7

Show Answer

Answer:

Correct Answer: A

Solution:

  • The midpoint of $ P(-2,6) $ and $ Q(4,2) $ is $ ( \frac{-2+4}{2},\frac{6+2}{2} ) $ i.e., $ (1,4) $ and the gradient of line$ PQ=\frac{2-6}{4+2}=\frac{-2}{3} $ \ The slope of $ L=\frac{3}{2} $ Hence the equation of line which passes through point $ (1,4) $ is $ y-4=\frac{3}{2}(x-1) $
    Þ $ 3x-2y+5=0 $ .