In: Advanced Math
(a) Given that, a,b are two nonzero vectors wose directions are inclined at .
The vector product of a & b is denoted as and it gives a vector quantity whose modulus value is and the direction is along the perpendicular to both vectors.
= where denoted as the unit vector perpendicular to both a & b.
(b) The position vectors of
A= 2i+j+3k, B = 4i-j+7k, C = -i-2j-2k , D = 2i-5j+k
then,
the equation of the line AB,
and the equation of line CD,
Any point of the line AB can be written as
Any point of the line CD can be written as
No such exists such that, =
Hence, AB, CD are skew.
Now, let the shortest distance line of AB and CD meets AB at E and CD at F.
Let, E=
and F=
Then, EF=
which is perpendicular to (2,-2,4) and (3,-3,3)
Then,
and
which gives
Then, the common perpendicular vector EF= (-3i-3j+0k)
and the shortest distance d= unit