Answer:
Magnitude: 3√10
Direction angle: 71.56°
Step-by-step explanation:
The magnitude ||v|| of a vector <a,b>, would be:
[tex]||v||=\sqrt{a^{2}+b^{2}[/tex]
[tex]||v||=\sqrt{3^{2}+9^{2}[/tex]
[tex]||v||=\sqrt{9+81}[/tex]
[tex]||v||=\sqrt{90}[/tex]
[tex]||v||=3\sqrt{10}[/tex]
The vector's reference angle would be:
[tex]tan\alpha =|\frac{b}{a}|[/tex]
[tex]tan\alpha =|\frac{9}{3}|[/tex]
[tex]tan\alpha =|3|[/tex]
[tex]tan\alpha =3[/tex]
[tex]\alpha = 71.56[/tex]
If [tex]\alpha[/tex] is your reference angle, then your direction angle ∅ depends on what quadrant the vector is located in. Since <3,9> is located in Quadrant I, then ∅= [tex]\alpha[/tex], which means your direction angle is also 71.56°
