Question

For the point \[(5,2,-4)\], what is its position vector \[\vec{a}\]?

Options

• \[\vec{a}=5\hat{i}-2\hat{j}-4\hat{k}\]

• \[\vec{a}=5\hat{i}+2\hat{j}+4\hat{k}\]

• \[\vec{a}=5\hat{i}+2\hat{j}-4\hat{k}\]

• \[\vec{a}=3\hat{i}+2\hat{j}-8\hat{k}\]

Answer 1

The coefficients of \[\hat{i},\hat{j},\hat{k}\] are the coordinates of the point in their given order. The third coordinate is \[-4\], so the \[\hat{k}\]-term is negative.