SPS SPS SM Pure 2021 May — Question 3 6 marks

Exam BoardSPS
ModuleSPS SM Pure (SPS SM Pure)
Year2021
SessionMay
Marks6
TopicVectors Introduction & 2D
TypeParallel or perpendicular vectors condition
DifficultyModerate -0.8 This is a straightforward multi-part vector question testing basic concepts: direction angle (tan 45° = 1), parallel vectors (proportional components), and unit vector magnitude. All parts require only direct application of standard formulas with minimal algebraic manipulation, making it easier than average A-level content.
Spec1.10a Vectors in 2D: i,j notation and column vectors1.10c Magnitude and direction: of vectors1.10d Vector operations: addition and scalar multiplication

Vector \(\mathbf{v} = a\mathbf{i} + 0.6\mathbf{j}\), where \(a\) is a constant.
  1. Given that the direction of \(\mathbf{v}\) is \(45°\), state the value of \(a\). [1]
  2. Given instead that \(\mathbf{v}\) is parallel to \(8\mathbf{i} + 3\mathbf{j}\), find the value of \(a\). [2]
  3. Given instead that \(\mathbf{v}\) is a unit vector, find the possible values of \(a\). [3]

Vector $\mathbf{v} = a\mathbf{i} + 0.6\mathbf{j}$, where $a$ is a constant.

\begin{enumerate}[label=(\roman*)]
\item Given that the direction of $\mathbf{v}$ is $45°$, state the value of $a$. [1]

\item Given instead that $\mathbf{v}$ is parallel to $8\mathbf{i} + 3\mathbf{j}$, find the value of $a$. [2]

\item Given instead that $\mathbf{v}$ is a unit vector, find the possible values of $a$. [3]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS SM Pure 2021 Q3 [6]}}