OCR MEI C3 — Question 2 5 marks

Exam BoardOCR MEI
ModuleC3 (Core Mathematics 3)
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicDifferentiating Transcendental Functions
TypeFind gradient at a point - direct evaluation
DifficultyStandard +0.3 This is a straightforward chain rule differentiation followed by direct substitution. While it involves transcendental functions (ln and trig), the technique is standard C3 material requiring dy/dx = 2sin(2x)/(1-cos(2x)) then evaluating at x=π/6. The algebra is routine and no problem-solving insight is needed, making it slightly easier than average.
Spec1.07l Derivative of ln(x): and related functions1.07r Chain rule: dy/dx = dy/du * du/dx and connected rates

2 Find the exact gradient of the curve \(y = \ln ( 1 - \cos 2 x )\) at the point with \(x\)-coordinate \(\frac { 1 } { 6 } \pi\).

Question 2
M1 \(1/(1 - \cos 2x)\) seen or implied
M1 \(\frac{d}{dx}(1 - \cos 2x) = \pm 2\sin 2x\)
A1cao \(\frac{dy}{dx} = \frac{2\sin 2x}{1 - \cos 2x}\)
M1 substituting \(\pi/6\) or \(30°\) into their derivative (must be in at least two places)
A1cao \(2\sqrt{3}\)
Guidance: isw after correct answer seen
Total: [5]
# Question 2

**M1** $1/(1 - \cos 2x)$ seen or implied

**M1** $\frac{d}{dx}(1 - \cos 2x) = \pm 2\sin 2x$

**A1cao** $\frac{dy}{dx} = \frac{2\sin 2x}{1 - \cos 2x}$

**M1** substituting $\pi/6$ or $30°$ into their derivative (must be in at least two places)

**A1cao** $2\sqrt{3}$

**Guidance:** isw after correct answer seen

**Total: [5]**
2 Find the exact gradient of the curve $y = \ln ( 1 - \cos 2 x )$ at the point with $x$-coordinate $\frac { 1 } { 6 } \pi$.

\hfill \mbox{\textit{OCR MEI C3  Q2 [5]}}