SPS SPS SM 2025 February — Question 7 8 marks

Exam BoardSPS
ModuleSPS SM (SPS SM)
Year2025
SessionFebruary
Marks8
TopicStandard trigonometric equations
TypeDeduce related solution
DifficultyStandard +0.3 Part (a) requires standard trigonometric manipulation using tan x = sin x/cos x and the Pythagorean identity, which is routine A-level technique. Part (b) applies the result with a double angle substitution and requires careful consideration of the range, adding modest problem-solving demand. Overall slightly easier than average due to the guided structure and standard methods.
Spec1.05j Trigonometric identities: tan=sin/cos and sin^2+cos^2=11.05o Trigonometric equations: solve in given intervals

  1. Show that the equation $$2 \sin x \tan x = \cos x + 5$$ can be expressed in the form $$3 \cos^2 x + 5 \cos x - 2 = 0.$$ [3]
  2. Hence solve the equation $$2 \sin 2\theta \tan 2\theta = \cos 2\theta + 5,$$ giving all values of \(\theta\) between \(0°\) and \(180°\), correct to \(1\) decimal place. [5]

\begin{enumerate}[label=(\alph*)]
\item Show that the equation
$$2 \sin x \tan x = \cos x + 5$$
can be expressed in the form
$$3 \cos^2 x + 5 \cos x - 2 = 0.$$ [3]

\item Hence solve the equation
$$2 \sin 2\theta \tan 2\theta = \cos 2\theta + 5,$$
giving all values of $\theta$ between $0°$ and $180°$, correct to $1$ decimal place. [5]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS SM 2025 Q7 [8]}}