If the position vector a of the point (5, n) is such that | a | = 13, then the value(s) of n can be

If | a | = 2 and | b | = 3, then, | a $$\times$$ b |² + | a . b |² is equal to

Consider the following inequalities in respect of vectors a and b

1. | a + b | $$\le$$ | a | + | b |

2. | a $$-$$ b | $$\ge$$ | a | $$-$$ | b |

Which of the above is/are correct?

If the magnitude of difference of two unit vectors is $$\sqrt 3 $$, then the magnitude of sum of the two vectors is