Question

Consider three vectors
A=4i+6j-2k
B=2i+7j-1k
C=0i+3j+5k
1) Write the expression for 2A?
2) What is A+B?
3) What is C-A?
4) What is CxA?

Answer 1

Explanation:

1) expression for 2A

2A=2(4i+6j-2k)= 8i+12j-4k

2)A+B = 4i+6j-2k+2i+7j-k

=6i+13j-3k

3)C-A= 0i+3j+5k-4i-6j+2k

=-4i-3j+7k

4) C×A=

|i j k |

|0 3 5 |

|4 6 2 |

=i[(3×2)-(6×5)] -j[(0×2)-(4×5)] +k[(0×6)-(4×3)]

C×A = -24i+20j-12k