1. Find AxB
`A=(3,1,1)`,`B=(-1,2,1)`

Solution:
Here `vec A=(3,1,1),vec B=(-1,2,1)`

`vec A xx vec B`

`=|[i,j,k],[A_1,A_2,A_3],[B_1,B_2,B_3]|`

`=|[i,j,k],[3,1,1],[-1,2,1]|`

`=i(1xx1-1xx2)-j(3xx1-1xx(-1))+k(3xx2-1xx(-1))`

`=i(1-2)-j(3+1)+k(6+1)`

`=-i-4j+7k`

`=(-1,-4,7)`

---

2. Find BxA
`A=(2,3,1)`,`B=(0,5,6)`

Solution:
Here `vec A=(2,3,1),vec B=(0,5,6),vec C=(2,3,1)`


`vec B xx vec A`

`=|[i,j,k],[B_1,B_2,B_3],[A_1,A_2,A_3]|`

`=|[i,j,k],[0,5,6],[2,3,1]|`

`=i(5xx1-6xx3)-j(0xx1-6xx2)+k(0xx3-5xx2)`

`=i(5-18)-j(0-12)+k(0-10)`

`=-13i+12j-10k`

`=(-13,12,-10)`

---

---

---