Let v=4i+8j\displaystyle {v}={4}\vec{{i}}+{8}\vec{{j}} and w=4i+2j\displaystyle {w}={4}\vec{{i}}+{2}\vec{{j}}.

Find a number c\displaystyle {c} so that wcv\displaystyle {w}-{c}{v} is perpendicular to v\displaystyle {v}.

c=\displaystyle {c}=