Chapter 2, Problem 70P

(a) If $\stackrel{\to }{\text{A}}\times \stackrel{\to }{\text{F}}=\stackrel{\to }{\text{B}}\times \stackrel{\to }{\text{F}}$ , can we conclude $\stackrel{\to }{\text{A}}=\stackrel{\to }{\text{B}}$ ? (b) If $\stackrel{\to }{\text{A}}\cdot \stackrel{\to }{\text{F}}=\stackrel{\to }{\text{B}}\cdot \stackrel{\to }{\text{F}}$ , can we conclude $\stackrel{\to }{\text{A}}=\stackrel{\to }{\text{B}}$ ? (c) If $F\stackrel{\to }{\text{A}}=\stackrel{\to }{\text{B}}F$ , can we conclude $\stackrel{\to }{\text{A}}=\stackrel{\to }{\text{B}}$ ? Why or why not?