Answer:
[tex]\sqrt{65}[/tex]
Step-by-step explanation:
The magnitude of a vector < x, y > is calculated as
| < x, y > | = [tex]\sqrt{x^2+y^2}[/tex]
Thus
j + k = < - 2, 1 > + < - 5, 3 > = < - 2 - 5, 1 + 3 > = < - 7, 4 >
Then
| < - 7, 4 > | = [tex]\sqrt{(-7)^2+4^2}[/tex] = [tex]\sqrt{49+16}[/tex] = [tex]\sqrt{65}[/tex]
