|a|=\sqrt{4^2+2^2+1^2}=\sqrt{21}\\
|b|=\sqrt{(-4)^2+4^2+3^2}=\sqrt{41}\\
a+b=(4-2;2+2;1+3)=(2;4;4)\\
|a+b|=6
" alt="
|a|=\sqrt{4^2+2^2+1^2}=\sqrt{21}\\
|b|=\sqrt{(-4)^2+4^2+3^2}=\sqrt{41}\\
a+b=(4-2;2+2;1+3)=(2;4;4)\\
|a+b|=6
" align="absmiddle" class="latex-formula">