Edexcel C2 — Question 3 8 marks

Exam BoardEdexcel
ModuleC2 (Core Mathematics 2)
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicStandard trigonometric equations
TypeMultiple independent equations — all direct solve
DifficultyModerate -0.8 Part (a) is a straightforward application of knowing when cosine equals zero (90° and 270°), requiring simple angle manipulation. Part (b) involves using the inverse sine function and finding all solutions in the given range using symmetry, which is a standard C2 technique. Both parts are routine exercises with clear procedures and no problem-solving insight required, making this easier than average.
Spec1.05o Trigonometric equations: solve in given intervals

Find all values of \(\theta\) in the interval \(0 \leq \theta < 360\) for which
  1. \(\cos(\theta + 75)^\circ = 0\). [3]
  2. \(\sin 2\theta^\circ = 0.7\), giving your answers to one decimal place. [5]

Find all values of $\theta$ in the interval $0 \leq \theta < 360$ for which

\begin{enumerate}[label=(\alph*)]
\item $\cos(\theta + 75)^\circ = 0$. [3]
\item $\sin 2\theta^\circ = 0.7$, giving your answers to one decimal place. [5]
\end{enumerate}

\hfill \mbox{\textit{Edexcel C2  Q3 [8]}}