Let → a and → b be two vectors such that | → b | = 1 and | → b × →...

Given: $\left|\overset{\to}{b}\right| = 1, \left|\overset{\to}{b} \times \overset{\to}{a}\right| = 2$

Now, solving ${\left|\overset{\to}{b} \times \overset{\to}{a} - \overset{\to}{b}\right|}^{2}$,

$⇒ {\left|\overset{\to}{b} \times \overset{\to}{a} - \overset{\to}{b}\right|}^{2} = {\left|\overset{\to}{b} \times \overset{\to}{a}\right|}^{2} + {\left|\overset{\to}{b}\right|}^{2} - 2\left(\overset{\to}{b} \times \overset{\to}{a}\right) \cdot \overset{\to}{b}$

Now, we know that, \left(\overset{\to}{b} \times \overset{\to}{a}\right) \cdot \overset{\to}{b} = \left(\overset{\to}{b} \times \overset{\to}{a}\right) \cdot \overset{\to}{a} = 0$</p><p>$⇒ {\left|\overset{\to}{b} \times \overset{\to}{a} - \overset{\to}{b}\right|}^{2} = {2}^{2} + {1}^{2} - 2 \times 0$</p><p>$⇒ {\left|\overset{\to}{b} \times \overset{\to}{a} - \overset{\to}{b}\right|}^{2} = 5