## Calculus (3rd Edition)

The length of $v$ is $$\|v\|=\sqrt{26}\approx 5.1.$$ Also, we have $$2v+3(4i-k)=18i-2j+5k.$$ With length $\sqrt{353}\approx 18.8$
The length of $v$ is given by $$\|v\|=\sqrt{9+1+16}=\sqrt{26}\approx 5.1.$$ Also, we have $$2v+3(4i-k)=6i-2j+8k+3(4i-k)=18i-2j+5k.$$ The length of this vector is: $\sqrt{18^2+(-2)^2+5^2}=\sqrt{18^2+4+25}=\sqrt{353}\approx 18.8$