rocedwrp

2021-01-15

It is given:

Yusuf Keller

Skilled2021-01-16Added 90 answers

Now

$\parallel m+3n{\parallel}^{2}=\u27e8m+3n,m+3n\u27e9=\u27e8m,m\u27e9+\u27e8m,3n\u27e9+\u27e83n,m\u27e9+\u27e83n,3n\u27e9=\parallel m{\parallel}^{2}+6\u27e8m,n\u27e9+9\parallel n{\parallel}^{2}=16+6\times 135+18=16+6\times 135+18=844$

Therefore

$\parallel m+3n\parallel =\sqrt{844}$

Therefore