Pre-U Pre-U 9794/1 2013 June — Question 6 3 marks

Exam BoardPre-U
ModulePre-U 9794/1 (Pre-U Mathematics Paper 1)
Year2013
SessionJune
Marks3
TopicTrig Graphs & Exact Values
TypeFind period or state transformations
DifficultyEasy -1.2 This is a straightforward question testing basic knowledge of trigonometric transformations. Part (i) requires sketching a standard transformed cosine graph with period π, and part (ii) asks for a simple description of a horizontal stretch by factor 1/2. Both parts are routine recall with minimal problem-solving, making this easier than average A-level content.
Spec1.02w Graph transformations: simple transformations of f(x)1.05f Trigonometric function graphs: symmetries and periodicities

6
  1. Sketch the graph of \(y = \cos 2 x\) for \(0 \leqslant x \leqslant 2 \pi\).
  2. Describe the transformation which maps the graph of \(y = \cos x\) onto the graph of \(y = \cos 2 x\).

(i) Two 'cos' curves shown in the range — B1
\(+1\) and \(-1\) shown on \(y\)-axis and \(x\) values for at least stationary points indicated on fully correct curve. (For the second B1, curves must show the stationary point at \(2\pi\) clearly.) — B1 [2]
(ii) State 'stretch' — B1
parallel to the \(x\)-axis — B1
scale factor 0.5 — B1 [3]
**(i)** Two 'cos' curves shown in the range — B1

$+1$ and $-1$ shown on $y$-axis and $x$ values for at least stationary points indicated on fully correct curve. (For the second B1, curves must show the stationary point at $2\pi$ clearly.) — B1 **[2]**

**(ii)** State 'stretch' — B1

parallel to the $x$-axis — B1

scale factor 0.5 — B1 **[3]**
6 (i) Sketch the graph of $y = \cos 2 x$ for $0 \leqslant x \leqslant 2 \pi$.\\
(ii) Describe the transformation which maps the graph of $y = \cos x$ onto the graph of $y = \cos 2 x$.

\hfill \mbox{\textit{Pre-U Pre-U 9794/1 2013 Q6 [3]}}