OCR MEI C2 — Question 5 3 marks

Exam BoardOCR MEI
ModuleC2 (Core Mathematics 2)
Marks3
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicTrig Graphs & Exact Values
TypeFind exact trig values from given ratio
DifficultyModerate -0.8 This is a straightforward application of Pythagoras to find the adjacent side from sin θ, then calculating tan θ = opposite/adjacent. It requires only basic trig definitions and one algebraic manipulation (√(9-2)/√2 = √7/√2), making it easier than average but not trivial since exact value manipulation is required.
Spec1.05j Trigonometric identities: tan=sin/cos and sin^2+cos^2=1

5 You are given that \(\sin \theta = \frac { \sqrt { 2 } } { 3 }\) and that \(\theta\) is an acute angle. Find the exact value of \(\tan \theta\).

Question 5:
Right angled triangle with \(\sqrt{2}\) on one side and 3 on hypotenuse
Pythagoras used to obtain remaining side \(= \sqrt{7}\)
M1 for \(\tan\theta = \frac{\text{opp}}{\text{adj}} = \frac{\sqrt{2}}{\sqrt{7}}\) or equivalent
A1 for \(\cos\theta = \frac{\sqrt{7}}{3}\)
M1 for \(\cos^2\theta = 1 - \sin^2\theta\) used
A1 for \(\cos\theta = \frac{\sqrt{7}}{3}\)
A1 for \(\tan\theta = \frac{\sin\theta}{\cos\theta} = \frac{\sqrt{2}}{\sqrt{7}}\) or equivalent
Question 5:

Right angled triangle with $\sqrt{2}$ on one side and 3 on hypotenuse

Pythagoras used to obtain remaining side $= \sqrt{7}$

M1 for $\tan\theta = \frac{\text{opp}}{\text{adj}} = \frac{\sqrt{2}}{\sqrt{7}}$ or equivalent

A1 for $\cos\theta = \frac{\sqrt{7}}{3}$

M1 for $\cos^2\theta = 1 - \sin^2\theta$ used

A1 for $\cos\theta = \frac{\sqrt{7}}{3}$

A1 for $\tan\theta = \frac{\sin\theta}{\cos\theta} = \frac{\sqrt{2}}{\sqrt{7}}$ or equivalent
5 You are given that $\sin \theta = \frac { \sqrt { 2 } } { 3 }$ and that $\theta$ is an acute angle. Find the exact value of $\tan \theta$.

\hfill \mbox{\textit{OCR MEI C2  Q5 [3]}}