CAIE FP1 2004 November — Question 7 8 marks

Exam BoardCAIE
ModuleFP1 (Further Pure Mathematics 1)
Year2004
SessionNovember
Marks8
PaperDownload PDF ↗
TopicImplicit equations and differentiation
TypeFind second derivative d²y/dx²
DifficultyStandard +0.8 This is a Further Maths implicit differentiation question requiring two applications of the technique. Part (i) is standard FP1 fare, but part (ii) requires differentiating the first derivative expression implicitly again, which involves careful application of quotient/product rules and substitution. The algebraic manipulation is non-trivial but follows established procedures for second derivatives of implicit functions.
Spec1.07s Parametric and implicit differentiation

7 The curve \(C\) has equation $$x y + ( x + y ) ^ { 5 } = 1$$
  1. Show that \(\frac { \mathrm { d } y } { \mathrm {~d} x } = - \frac { 5 } { 6 }\) at the point \(A ( 1,0 )\) on \(C\).
  2. Find the value of \(\frac { \mathrm { d } ^ { 2 } y } { \mathrm {~d} x ^ { 2 } }\) at \(A\).

7 The curve $C$ has equation

$$x y + ( x + y ) ^ { 5 } = 1$$

(i) Show that $\frac { \mathrm { d } y } { \mathrm {~d} x } = - \frac { 5 } { 6 }$ at the point $A ( 1,0 )$ on $C$.\\
(ii) Find the value of $\frac { \mathrm { d } ^ { 2 } y } { \mathrm {~d} x ^ { 2 } }$ at $A$.

\hfill \mbox{\textit{CAIE FP1 2004 Q7 [8]}}