1. Find isLinearlyDependant(A,B,C)
`A=(1,2,3)`,`B=(4,5,6)`,`C=(7,8,9)`

Solution:
Here `vec A=(1,2,3),vec B=(4,5,6),vec C=(7,8,9)`

The vectors A, B, C are linearly dependent, if their determinant is zero. i.e. `|D|=0`

`|D|`

=

`1`   `2`   `3`   `4`   `5`   `6`   `7`   `8`   `9`

=

`1`   ×    `5`   `6`   `8`   `9`

`-2`   ×    `4`   `6`   `7`   `9`

`+3`   ×    `4`   `5`   `7`   `8`

`=1 xx (5 × 9 - 6 × 8) -2 xx (4 × 9 - 6 × 7) +3 xx (4 × 8 - 5 × 7)`

`=1 xx (45 -48) -2 xx (36 -42) +3 xx (32 -35)`

`=1 xx (-3) -2 xx (-6) +3 xx (-3)`

`= -3 +12 -9`

`=0`


Since `|D|=0`, So vectors A, B, C are linearly dependent.