Respuesta :

The answer is the option C 

Find unit vector.

Definition of unit vector :

u is a unit vector, it has the same direction as then 

v--------------(7,-9)         (-17,4)

v=(-24,13)

u is a unit vector, it has the same direction as v

magnitude of v---------(-24^2+13^2)^0.5=725^0.5

 u=(-24/(725)^.5),(13/(725)^.5)



Answer:

[tex]u_{v}=-\frac{24}{\sqrt{745} }i +\frac{13}{\sqrt{745} } j[/tex]

Step-by-step explanation:

The initial point of the vector is at (7,-9).

The terminal point of the vector is at (-17,4).

First, we need to find the same vector with initial point at the origin of the coordinate system. We do that by finding its horizontal length and its vertical length.

[tex]\Delta x = -17 - 7=-24\\\Delta y = 4-(-9)=13[/tex]

So, the vector with initial point at the origin is

[tex]v=-24i+13j[/tex]

Where [tex]i[/tex] represents horizontal direction and [tex]j[/tex] represents vertical direction.

Now, we need to find the module of this vector

[tex]|v|=\sqrt{(-24)^{2}+(13)^{2} }=\sqrt{576+169}\\ |v|=\sqrt{745}[/tex]

The uni vector is defined by the quotient between the vector and its module.

[tex]u_{v} =\frac{v}{|v|}[/tex]

Replacing each part, we have

[tex]u_{v}=\frac{-24i+13j}{\sqrt{745} }\\ u_{v}=-\frac{24}{\sqrt{745} }i +\frac{13}{\sqrt{745} } j[/tex]

Therefore, the right answer is the third choice.