OCR H240/01 2018 June — Question 10 10 marks

Exam BoardOCR
ModuleH240/01 (Pure Mathematics)
Year2018
SessionJune
Marks10
PaperDownload PDF ↗
TopicParametric curves and Cartesian conversion
TypeConvert to Cartesian (polynomial/rational)
DifficultyStandard +0.3 This is a straightforward parametric equations question requiring standard techniques: differentiation using the chain rule (part i), interpretation of gradient (part ii), and elimination of parameter with a helpful hint provided (part iii). The algebraic manipulation is routine, making this slightly easier than average for A-level.
Spec1.03g Parametric equations: of curves and conversion to cartesian1.07s Parametric and implicit differentiation

10 A curve has parametric equations \(x = t + \frac { 2 } { t }\) and \(y = t - \frac { 2 } { t }\), for \(t \neq 0\).
  1. Find \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) in terms of \(t\), giving your answer in its simplest form.
  2. Explain why the curve has no stationary points.
  3. By considering \(x + y\), or otherwise, find a cartesian equation of the curve, giving your answer in a form not involving fractions or brackets.

10 A curve has parametric equations $x = t + \frac { 2 } { t }$ and $y = t - \frac { 2 } { t }$, for $t \neq 0$.\\
(i) Find $\frac { \mathrm { d } y } { \mathrm {~d} x }$ in terms of $t$, giving your answer in its simplest form.\\
(ii) Explain why the curve has no stationary points.\\
(iii) By considering $x + y$, or otherwise, find a cartesian equation of the curve, giving your answer in a form not involving fractions or brackets.

\hfill \mbox{\textit{OCR H240/01 2018 Q10 [10]}}