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Grade 11Analytical Geometry

If the pairs of line represented by the equation (ax^2+2hxy+by^2+2gx+2fy+c=0) intersect each other on y axis which is not origin then which of following is/are true
(a) g^2=ac
(b) f^2=bc
(c) 2fgh=bg^2+ch^2
(d) hc=gf

Profile image of Adarsh Srivastav
9 Years agoGrade 11
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1 Answer

Profile image of Nishant Vora
9 Years ago
the condition for this eqn to be a pair of sl is
223-2443_Capture.PNG…...............(1)
now both the straight line is intersecting on y axis
so x= 0

Put x= 0 inax^2+2hxy+by^2+2gx+2fy+c=0

soby^2 +2fy+c=0

Now for this Quadratic y1 = y2 as there is a unique point

So D=0

So4f^2 - 4bc = 0

Hence,f^2 - bc = 0