1
my approach
7 Answers
1IN THIER SOLUTION THEY HAVE MADE THE FIRST PART = 0 AND THEY HAVE OMIITED OUT 'd' AND WHY THEY HAVE DONE SOO
please explain me .. and also show ur approach how to do da sum ;'( [17] [17]
1if a plane contains a line.
then,
the point on the line must satisfy the plane eqn. --- (1)
the direction cosines of line X dir cosine of plane =0 ---- (2)
by (1), a2 - 3bd - c2 =d
by (2), a2 - b2 - c2 =0
from these two,
b2=3bd+d
i have no idea how in the soln.. then have equated the second equation to zero... it has to be 'd'.
33playpower...
in ur approach..
λ(a2-b2-c2)+(a2+3bd-c2-d2)=0
what u can conclude from here....
For any real λ it is true... so each bracket must be zero...
hence
(a2-b2-c2)=0
and (a2+3bd-c2-d2)=0