Question

Determine the projection of u=1.6i+3.3j in the v=-2.1i-0.5j direction

Answer 1

answer is B i think on edg. 2.3i+0.5j

Explanation:

just took the test

Answer 2

The projection of
`\vec u` onto
`\vec v` is

`\mathrm{proj}_(\vec v)(\vec u)=(\vec u\cdot\vec v)/(\vec v\cdot\vec v)\vec v`

We have

`\vec u\cdot\vec v=1.6\cdot(-2.1)+3.3\cdot(-0.5)=-5.01`

`\vec v\cdot\vec v=\|\vec v\|^2=(-2.1)^2+(-0.5)^2=4.66`

`\implies\mathrm{proj}_(\vec v)(\vec u)=(-5.01)/(4.66)\vec v\approx2.26\,\vec\imath+0.54\,\vec\jmath`