Straight Line Question 355
Question: The equation of straight line passing through point of intersection of the straight lines $ 3x-y+2=0 $ and $ 5x-2y+7=0 $ and having infinite slope is [UPSEAT 2001]
Options:
A) $ x=2 $
B) $ x+y=3 $
C) $ x=3 $
D) $ x=4 $
Correct Answer: C
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Answer:
Solution:
Þ $ (3+5\lambda )x-(2\lambda +1)y+(2+7\lambda )=0 $
Þ $ y=\frac{3+5\lambda }{2\lambda +1}x+\frac{2+7\lambda }{2\lambda +1} $ ?..(ii) As the equation (ii), has infinite slope, $ 2\lambda +1=0 $
Þ $ \lambda =-1/2 $ putting $ \lambda =-1/2 $ in equation (i) we have $ (3x-y+2)+(-1/2)(5x-2y+7)=0 $
Þ $ x=3 $ .
BETA
