CAIE P3 2011 June — Question 2 4 marks

Exam BoardCAIE
ModuleP3 (Pure Mathematics 3)
Year2011
SessionJune
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicProduct & Quotient Rules
TypeFind derivative of quotient
DifficultyModerate -0.8 This is a straightforward two-part differentiation question testing standard rules (chain rule for part i, quotient rule for part ii). Both are routine applications with no problem-solving required, making it easier than average but not trivial since it requires correct application of multiple differentiation rules.
Spec1.07l Derivative of ln(x): and related functions1.07q Product and quotient rules: differentiation1.07r Chain rule: dy/dx = dy/du * du/dx and connected rates

2 Find \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) in each of the following cases:
  1. \(y = \ln ( 1 + \sin 2 x )\),
  2. \(y = \frac { \tan x } { x }\).

Question 2:
Part (i):
AnswerMarks Guidance
Answer/WorkingMark Guidance
Obtain \(\frac{k\cos 2x}{1+\sin 2x}\) for any non-zero constant \(k\)M1
Obtain \(\frac{2\cos 2x}{1+\sin 2x}\)A1 [2]
Part (ii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
Use correct quotient or product ruleM1
Obtain \(\frac{x\sec^2 x - \tan x}{x^2}\) or equivalentA1 [2]
## Question 2:

### Part (i):

| Answer/Working | Mark | Guidance |
|---|---|---|
| Obtain $\frac{k\cos 2x}{1+\sin 2x}$ for any non-zero constant $k$ | M1 | |
| Obtain $\frac{2\cos 2x}{1+\sin 2x}$ | A1 | [2] |

### Part (ii):

| Answer/Working | Mark | Guidance |
|---|---|---|
| Use correct quotient or product rule | M1 | |
| Obtain $\frac{x\sec^2 x - \tan x}{x^2}$ or equivalent | A1 | [2] |

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2 Find $\frac { \mathrm { d } y } { \mathrm {~d} x }$ in each of the following cases:\\
(i) $y = \ln ( 1 + \sin 2 x )$,\\
(ii) $y = \frac { \tan x } { x }$.

\hfill \mbox{\textit{CAIE P3 2011 Q2 [4]}}