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The equation `lambda(x^(3)-3xy^(2))+y^(3)-3x^(2)y=0` represent three straight lines passing through the origin such that
A. they are equally inclined to one another
B. two of which are at right angles
C. two of which are coincident
D. none of these

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Correct Answer - A
Let `y=mx` be one of the lines represented by the given equation. Then, `y=mx` satisfies it.
`therefore" "lambda(1-3m^(2))+m^(3)-3m=0`
`rArr" "lambda=(3m-m^(3))/(1-3m^(2))`
`rArr" "tan phi=(3tantheta- tan^(3)theta)/(13tan^(2)theta)`, where `lambda= tan phi and m = tan theta`
`rArr" "tan phi=tan 3 theta`
`rArr" "3 theta=phi, pi + phi, 2pi + phi`
`rArr" "theta=(phi)/(3),(pi)/(3)+(phi)/(3),(2pi)/(3)+(phi)/(3)`
Hence, the given equation represents three lines passing through the origin such that they are equally inclined with one another.

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