Questions: Problem A. 10
Find the magnitude of the vector u and a unit vector in the direction of the vector u. Do not approximate square roots and fractions as decimals.
A.10.a u = [3,-2]
Transcript text: Problem A. 10
Find $\|\overrightarrow{\boldsymbol{u}}\|$ and a unit vector in the direction of $\overrightarrow{\boldsymbol{u}}$. Do not approximate square roots and fractions as decimals.
\[
\text { A.10.a } \vec{u}=[3,-2]
\]
Solution
Solution Steps
To find the magnitude of the vector \(\vec{u}\), we use the formula \(\|\vec{u}\| = \sqrt{u_1^2 + u_2^2}\). To find a unit vector in the direction of \(\vec{u}\), we divide each component of \(\vec{u}\) by its magnitude.
Solution Approach
Calculate the magnitude of \(\vec{u}\) using the formula \(\|\vec{u}\| = \sqrt{u_1^2 + u_2^2}\).
Find the unit vector by dividing each component of \(\vec{u}\) by its magnitude.
Step 1: Calculate the Magnitude of \(\vec{u}\)
The magnitude of the vector \(\vec{u} = [3, -2]\) is calculated using the formula:
\[
\|\vec{u}\| = \sqrt{3^2 + (-2)^2} = \sqrt{9 + 4} = \sqrt{13}
\]
Step 2: Calculate the Unit Vector in the Direction of \(\vec{u}\)
To find the unit vector in the direction of \(\vec{u}\), we divide each component of \(\vec{u}\) by its magnitude:
\[
\text{Unit vector} = \left[ \frac{3}{\sqrt{13}}, \frac{-2}{\sqrt{13}} \right]
\]
Final Answer
The magnitude of \(\vec{u}\) is:
\[
\boxed{\|\vec{u}\| = \sqrt{13}}
\]
The unit vector in the direction of \(\vec{u}\) is:
\[
\boxed{\left[ \frac{3}{\sqrt{13}}, \frac{-2}{\sqrt{13}} \right]}
\]