WJEC Unit 1 2018 June — Question 3

Exam BoardWJEC
ModuleUnit 1 (Unit 1)
Year2018
SessionJune
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicStandard trigonometric equations
TypeConvert to quadratic in sin/cos
DifficultyModerate -0.8 This is a standard trigonometric equation requiring the Pythagorean identity (cos²θ = 1 - sin²θ) to convert to a quadratic in sin θ, then solving a straightforward quadratic equation and finding angles. It's a routine textbook exercise with well-practiced techniques, making it easier than average but not trivial due to the multi-step process.
Spec1.05j Trigonometric identities: tan=sin/cos and sin^2+cos^2=11.05o Trigonometric equations: solve in given intervals1.07i Differentiate x^n: for rational n and sums1.08c Integrate e^(kx), 1/x, sin(kx), cos(kx)

Solve the following equation for values of \(\theta\) between \(0 ^ { \circ }\) and \(360 ^ { \circ }\). $$2 - 3 \cos ^ { 2 } \theta = 2 \sin \theta$$
04
a) Given that \(y = \frac { 5 } { x } + 6 \sqrt [ 3 ] { x }\), find \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) when \(x = 8\). b) Find \(\int \left( 5 x ^ { \frac { 3 } { 2 } } + 12 x ^ { - 5 } + 7 \right) \mathrm { d } x\).
05
The diagram below shows a sketch of \(y = f ( x )\). \includegraphics[max width=\textwidth, alt={}, center]{805df86d-3115-4311-982a-263e114a9722-3_659_828_445_639}
a) Sketch the graph of \(y = 4 + f ( x )\), clearly indicating any asymptotes.
b) Sketch the graph of \(y = f ( x - 3 )\), clearly indicating any asymptotes.

0 6 \includegraphics[max width=\textwidth, alt={}, center]{805df86d-3115-4311-982a-263e114a9722-3_609_869_1491_619} The sketch shows the curve \(C\) with equation \(y = 14 + 5 x - x ^ { 2 }\) and line \(L\) with equation \(y = x + 2\). The line intersects the curve at the points \(A\) and \(B\).
a) Find the coordinates of \(A\) and \(B\).
b) Calculate the area enclosed by \(L\) and \(C\).
07
Prove that $$\frac { \sin ^ { 3 } \theta + \sin \theta \cos ^ { 2 } \theta } { \cos \theta } \equiv \tan \theta$$

Solve the following equation for values of $\theta$ between $0 ^ { \circ }$ and $360 ^ { \circ }$.

$$2 - 3 \cos ^ { 2 } \theta = 2 \sin \theta$$

\begin{center}
\begin{tabular}{ | l | l | }
\hline
0 & 4 \\
\hline
\end{tabular}
\end{center} a) Given that $y = \frac { 5 } { x } + 6 \sqrt [ 3 ] { x }$, find $\frac { \mathrm { d } y } { \mathrm {~d} x }$ when $x = 8$.

b) Find $\int \left( 5 x ^ { \frac { 3 } { 2 } } + 12 x ^ { - 5 } + 7 \right) \mathrm { d } x$.

\begin{center}
\begin{tabular}{ | l | l | }
\hline
0 & 5 \\
\hline
\end{tabular}
\end{center}

The diagram below shows a sketch of $y = f ( x )$.\\
\includegraphics[max width=\textwidth, alt={}, center]{805df86d-3115-4311-982a-263e114a9722-3_659_828_445_639}\\
a) Sketch the graph of $y = 4 + f ( x )$, clearly indicating any asymptotes.\\
b) Sketch the graph of $y = f ( x - 3 )$, clearly indicating any asymptotes.\\
□\\
0 6\\
\includegraphics[max width=\textwidth, alt={}, center]{805df86d-3115-4311-982a-263e114a9722-3_609_869_1491_619}

The sketch shows the curve $C$ with equation $y = 14 + 5 x - x ^ { 2 }$ and line $L$ with equation $y = x + 2$. The line intersects the curve at the points $A$ and $B$.\\
a) Find the coordinates of $A$ and $B$.\\
b) Calculate the area enclosed by $L$ and $C$.

\begin{center}
\begin{tabular}{ | l | l | }
\hline
0 & 7 \\
\hline
\end{tabular}
\end{center}

Prove that

$$\frac { \sin ^ { 3 } \theta + \sin \theta \cos ^ { 2 } \theta } { \cos \theta } \equiv \tan \theta$$

\hfill \mbox{\textit{WJEC Unit 1 2018 Q3}}