Just looking to answer section b iii only so u x vSolutionSo

Just looking to answer section b iii) only

so u x v

Solution

Solution(1)

|u|=sqrt[1² +(-4)² +2² ]

=sqrt(1+16+4)

sqrt(21)

=4.583

solution2:

u,v=u1v1+u2v2+u3v3

=(1)(-2)+(-4)(1)+(2)(0)

=-2-4+0

u.v =-6

Solution3:

uxv=

i j k

1 -4 2

-2 1 0

=i det[-4 2 -j det[ 1 2 +k[1 -4

-2 1]

-2 0]

1 0]

=i(-0-2)-j(0+4)+k(1-8)

uxv =-2i-4j-7k