Question

Find the unit vector that has the same direction as the vector v. v = 3i + j
(answer choices are pictured below)

Answer 1

$\bf \textit{unit vector for \underline{v}}\qquad v=\ \textless \ a,b\ \textgreater \ \implies \stackrel{unit~vector}{\cfrac{a}{\sqrt{a^2+b^2}}~,~\cfrac{b}{\sqrt{a^2+b^2}}}\\\\ -------------------------------\\\\ v=3i+j\implies v=\ \textless \ 3,1\ \textgreater \ \implies \stackrel{unit~vector}{\cfrac{3}{\sqrt{3^2+1^2}}~,~\cfrac{1}{\sqrt{3^2+1^2}}} \\\\\\ \left( \cfrac{3}{\sqrt{10}}~,~\cfrac{1}{\sqrt{10}} \right)$

Answer 2

Answer:

Step-by-step explanation:

Given is a vector v =3i+j

To find unit vector in the direction of v:

Since direction is the same as v we need not change the coefficients of i and j

But magnitude must be changed to 1.

Calculate the magnitude of vector v

|v|=\sqrt {3^2+1^2} =\sqrt{10}

TO make magnitude to 1 we divide the vector by magnitude

Hence unit vector

= \frac{1}{\sqrt{10}}(3i+j)