Let $\vec a,b$ be two vectors such that $|\vec a| = 2, |\vec b| = 3,\vec a.\vec b=4$, then $|\vec a-\vec b|$ is equal to |
0 $\sqrt{5}$ 5 1 |
$\sqrt{5}$ |
The correct answer is Option (2) → $\sqrt{5}$ Given $|\vec a|=2,\;|\vec b|=3,\;\vec a\cdot\vec b=4$ Use formula $|\vec a-\vec b|^{2}=|\vec a|^{2}+|\vec b|^{2}-2(\vec a\cdot\vec b)$ Substitute values $|\vec a-\vec b|^{2}=2^{2}+3^{2}-2(4)$ $=4+9-8$ $=5$ $|\vec a-\vec b|=\sqrt{5}$ |