Question
If $|\vec{\text{a}}|=2,\big|\vec{\text{b}}\big|=5$ and $\vec{\text{a}}.\vec{\text{b}}=2,$ find $\big|\hat{\text{a}}-\hat{\text{b}}\big|.$
$|\vec{\text{a}}|=2,\big|\vec{\text{b}}\big|=5$
and $\vec{\text{a}}.\vec{\text{b}}=2$ Now,$\big|\hat{\text{a}}-\hat{\text{b}}\big|^2=|\vec{\text{a}}|^2+\big|\vec{\text{b}}\big|^2-2\vec{\text{a}}.\vec{\text{b}}$
$=2^2+5^2-2(2)$
$=4+25-4$
$=25$
$\therefore\big|\vec{\text{a}}-\vec{\text{b}}\big|=\sqrt{25}=5$
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| X: | 0.5 | 1 | 1.5 | 2 |
| P(X): | k | k2 | 2k2 | k |
| X: | 0 | 1 | 2 |
| P(X): | 0.6 | 0.4 | 0.2 |