Question

Let $a$ and $b$ be perpendicular vectors such that $IaI=√104$ and $IbI=6$.Then the value of$Ia-bI$ is ?

• A. $√110$
• B. $√140$
• C. $√98$
• D. $√55$
• E. $√70$

Answer 1

Answer: (B)

$√140$

Answer 2

Given that

Let $a$ and $b$ be perpendicular vectors such that;

$IaI=√104$ and $IbI=6$.

We know that ,

$|a-b|^{2}=|a|^{2}+|b|^{2}-2.|a|.|b|cos90°$

$⇒|a-b|^{2}=104+36-0$

$⇒|a-b|=√140$ (Ans.)