Question

If $\overset{\rightarrow}{a}$and $\overset{\rightarrow}{b}$ are two unit vectors and $\overset{\rightarrow}{R} = \overset{\rightarrow}{a} + \overset{\rightarrow}{b}$and also if $|\overset{\rightarrow}{R|}$ = R, then –

• A. R < 0
• B. R > 2
• C. 0 £ R£ 2
• D. R must be 2

Answer 1

Answer: (C)

0 £ R£ 2

Answer 2

if $|\overset{\rightarrow}{R}|$ = $|\overset{\rightarrow}{a} + \overset{\rightarrow}{b}|$ then, (a – b) £ R £ (a + b)