Question

For \[\vec a_1=\hat i+\hat j\] and \[\vec a_2=2\hat i+\hat j-\hat k\], what is \[\vec a_2-\vec a_1\]?

Options

• \[\hat i+\hat k\]

• \[\hat i-\hat k\]

• \[-\hat i+\hat k\]

• \[3\hat i+2\hat j-\hat k\]

Answer 1

Subtract the corresponding components of \[\vec a_1\] from \[\vec a_2\]. The \[\hat j\] components cancel, leaving \[\hat i-\hat k\].