csat-suneung 2012 Q8

csat-suneung · South-Korea · csat__math-science 3 marks Vectors Introduction & 2D Magnitude of Vector Expression
In triangle ABC,
$$\overline { \mathrm { AB } } = 2 , \quad \angle \mathrm {~B} = 90 ^ { \circ } , \quad \angle \mathrm { C } = 30 ^ { \circ }$$
When point P satisfies $\overrightarrow { \mathrm { PB } } + \overrightarrow { \mathrm { PC } } = \overrightarrow { 0 }$, what is the value of $| \overrightarrow { \mathrm { PA } } | ^ { 2 }$? [3 points]
(1) 5
(2) 6
(3) 7
(4) 8
(5) 9
In triangle ABC,

$$\overline { \mathrm { AB } } = 2 , \quad \angle \mathrm {~B} = 90 ^ { \circ } , \quad \angle \mathrm { C } = 30 ^ { \circ }$$

When point P satisfies $\overrightarrow { \mathrm { PB } } + \overrightarrow { \mathrm { PC } } = \overrightarrow { 0 }$, what is the value of $| \overrightarrow { \mathrm { PA } } | ^ { 2 }$? [3 points]\\
(1) 5\\
(2) 6\\
(3) 7\\
(4) 8\\
(5) 9