Question

Three vectors and add up to zero. Find which is false

• A. $( \overrightarrow { \mathrm { A } } \times \overrightarrow { \mathrm { B } } ) \times \overrightarrow { \mathrm { C } }$ is not zero unless are parallel
• B. is not zero unless $\overrightarrow { \mathrm { B } } , \overrightarrow { \mathrm { C } }$ are parallel
• C. If define a plane, $( \overrightarrow { \mathrm { A } } \times \overrightarrow { \mathrm { B } } ) \times \overrightarrow { \mathrm { C } }$ is in that plane
• D. $( \overrightarrow { \mathrm { A } } \times \overrightarrow { \mathrm { B } } ) \cdot \overrightarrow { \mathrm { C } } = | \overrightarrow { \mathrm { A } } \| \overrightarrow { \mathrm { B } } \| \overrightarrow { \mathrm { C } } | \rightarrow \mathrm { C } ^ { 2 } = \mathrm { A } ^ { 2 } + \mathrm { B } ^ { 2 }$

Answer 1

Answer: (C)

If define a plane, $( \overrightarrow { \mathrm { A } } \times \overrightarrow { \mathrm { B } } ) \times \overrightarrow { \mathrm { C } }$ is in that plane