SPS SPS FM Pure 2024 February — Question 11 7 marks

Exam BoardSPS
ModuleSPS FM Pure (SPS FM Pure)
Year2024
SessionFebruary
Marks7
TopicVectors 3D & Lines
TypeLine-plane intersection and related angle/perpendicularity
DifficultyChallenging +1.8 This is a challenging Further Maths question requiring understanding of when three planes don't meet at a unique point (determinant = 0), solving for parameter values, then analyzing two different geometric configurations (likely parallel planes vs. sheaf). It demands matrix/determinant work, algebraic manipulation, and geometric interpretation—significantly above average difficulty but standard for FM Pure.
Spec4.03s Consistent/inconsistent: systems of equations4.03t Plane intersection: geometric interpretation

Three planes have equations \begin{align} (4k + 1)x - 3y + (k - 5)z &= 3
(k - 1)x + (3 - k)y + 2z &= 1
7x - 3y + 4z &= 2 \end{align}
  1. The planes do not meet at a unique point. Show that \(k = 4.5\) is one possible value of \(k\), and find the other possible value of \(k\). [3 marks]
  2. For each value of \(k\) found in part (a), identify the configuration of the given planes. In each case fully justify your answer, stating whether or not the equations of the planes form a consistent system. [4 marks]

Three planes have equations
\begin{align}
(4k + 1)x - 3y + (k - 5)z &= 3 \\
(k - 1)x + (3 - k)y + 2z &= 1 \\
7x - 3y + 4z &= 2
\end{align}

\begin{enumerate}[label=(\alph*)]
\item The planes do not meet at a unique point.

Show that $k = 4.5$ is one possible value of $k$, and find the other possible value of $k$. [3 marks]

\item For each value of $k$ found in part (a), identify the configuration of the given planes.

In each case fully justify your answer, stating whether or not the equations of the planes form a consistent system. [4 marks]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS FM Pure 2024 Q11 [7]}}