p3 maths

[princesszahra]

doubt in vecotr question
june 09
q9
ii
i know to solve vector
but this one.......i dont get the ans

 

[Jazib]

u solved, but answer is coming out wrong? what method u used?

 

[Buffer Solution]

Well, this is how i attempted it.
i put t=0 in the eq of line.....and put the point in the plane eq.
forming an eq in terms of b and c.
then i took the dot product of normal to the plane and the directional vector of the line and put it =0
so i got another eq relating b and c..
then i solved them simultaneously....
part ii is simple..so i didn't attenpt it..but i think it could be done like this...you calculate AP....assuming A is a point where t=0
find the vector product of AP and the directional vector of l.
then take the modulus of this new found vector and divide it by the modulus of the directional vector. i dont knw the answer but try it, i think it will yield the right answer. hope this helps..

 

[princesszahra]

i have doubt in the second part!
plz explain!

 

[Buffer Solution]

i just solved it....first find AP=OP-OA
then take the cross product of AP and directional vector of l
take the modulus of the answer
and divide it by the modulus of directional vector..
it wud be something like...underroot 45 over underroot 9...