Question

va rog calculati lungimea lui v

Answer 1

[tex]\text{Daca avem vectorul:} \vec{v}=a\cdot \vec{i}+b\cdot \vec{j},\text{atunci lungimea lui}\ \vec{v}\ \text{este:}\\ |\vec{v}|=\sqrt{a^2+b^2}\\ \text{In cazul nostru va fi:}\\ |\vec{v_n}|=\sqrt{(n^2-1)^2+4n^2}=\sqrt{n^4-2n^2+1+4n^2}=\sqrt{n^4+2n^2+1}=\\ =\sqrt{(n^2+1)^2}= |n^2+1|=n^2+1 [/tex]