OCR C4 — Question 4 8 marks

Exam BoardOCR
ModuleC4 (Core Mathematics 4)
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicParametric curves and Cartesian conversion
TypeConvert to Cartesian (tan/sec/cot/cosec identities)
DifficultyStandard +0.3 This is a straightforward parametric equations question requiring standard techniques: (i) uses the identity sec²θ = 1 + tan²θ to eliminate the parameter, and (ii) applies a given substitution for integration. Both parts follow well-practiced methods with no novel insight required, making it slightly easier than average.
Spec1.03g Parametric equations: of curves and conversion to cartesian1.08e Area between curve and x-axis: using definite integrals1.08h Integration by substitution

4. \includegraphics[max width=\textwidth, alt={}, center]{c7b867af-0730-459e-9c76-15eb07b9e476-1_465_976_1539_388} The diagram shows the curve with parametric equations $$x = \tan \theta , \quad y = \cos ^ { 2 } \theta , \quad - \frac { \pi } { 2 } < \theta < \frac { \pi } { 2 }$$
  1. Find a cartesian equation for the curve. The shaded region is bounded by the curve, the \(x\)-axis and the lines \(x = - 1\) and \(x = 1\).
  2. Using integration, with the substitution \(x = \tan u\), find the area of the shaded region.

4.\\
\includegraphics[max width=\textwidth, alt={}, center]{c7b867af-0730-459e-9c76-15eb07b9e476-1_465_976_1539_388}

The diagram shows the curve with parametric equations

$$x = \tan \theta , \quad y = \cos ^ { 2 } \theta , \quad - \frac { \pi } { 2 } < \theta < \frac { \pi } { 2 }$$

(i) Find a cartesian equation for the curve.

The shaded region is bounded by the curve, the $x$-axis and the lines $x = - 1$ and $x = 1$.\\
(ii) Using integration, with the substitution $x = \tan u$, find the area of the shaded region.\\

\hfill \mbox{\textit{OCR C4  Q4 [8]}}