Rational curve intersections

Questions involving sketching a rational function (reciprocal or reciprocal squared) with another curve (polynomial or linear) to determine number of intersections or solve equations.

8 questions

Edexcel P1 2022 January Q10
10. The curve \(C\) has equation $$y = \frac { 1 } { x ^ { 2 } } - 9$$
  1. Sketch the graph of \(C\). On your sketch
    • show the coordinates of any points of intersection with the coordinate axes
    • state clearly the equations of any asymptotes
    The curve \(D\) has equation \(y = k x ^ { 2 }\) where \(k\) is a constant. Given that \(C\) meets \(D\) at 4 distinct points,
  2. find the range of possible values for \(k\).
Edexcel P1 2020 October Q7
7. The curve \(C\) has equation $$y = \frac { 1 } { 2 - x }$$
  1. Sketch the graph of \(C\). On your sketch you should show the coordinates of any points of intersection with the coordinate axes and state clearly the equations of any asymptotes. The line \(l\) has equation \(y = 4 x + k\), where \(k\) is a constant. Given that \(l\) meets \(C\) at two distinct points,
  2. show that $$k ^ { 2 } + 16 k + 48 > 0$$
  3. Hence find the range of possible values for \(k\).
Edexcel C1 2009 January Q8
8. The point \(P ( 1 , a )\) lies on the curve with equation \(y = ( x + 1 ) ^ { 2 } ( 2 - x )\).
  1. Find the value of \(a\).
  2. On the axes below sketch the curves with the following equations:
    1. \(y = ( x + 1 ) ^ { 2 } ( 2 - x )\),
    2. \(y = \frac { 2 } { x }\). On your diagram show clearly the coordinates of any points at which the curves meet the axes.
  3. With reference to your diagram in part (b) state the number of real solutions to the equation $$( x + 1 ) ^ { 2 } ( 2 - x ) = \frac { 2 } { x } .$$
    \includegraphics[max width=\textwidth, alt={}]{871f5957-180d-4379-88ce-186432f57bad-10_1347_1344_1245_297}
Edexcel C1 2011 January Q10
10. (a) On the axes below, sketch the graphs of
  1. \(y = x ( x + 2 ) ( 3 - x )\)
  2. \(y = - \frac { 2 } { x }\)
    showing clearly the coordinates of all the points where the curves cross the coordinate axes.
    (b) Using your sketch state, giving a reason, the number of real solutions to the equation $$x ( x + 2 ) ( 3 - x ) + \frac { 2 } { x } = 0$$ \includegraphics[max width=\textwidth, alt={}, center]{95e11fd7-765c-477d-800b-7574bc1af81f-13_994_997_1270_479}
OCR C1 Q4
4. (i) Sketch on the same diagram the curves \(y = x ^ { 2 } - 4 x\) and \(y = - \frac { 1 } { x }\).
(ii) State, with a reason, the number of real solutions to the equation $$x ^ { 2 } - 4 x + \frac { 1 } { x } = 0 .$$
Edexcel C1 Q4
4. (a) Sketch on the same diagram the curves \(y = x ^ { 2 } - 4 x\) and \(y = - \frac { 1 } { x }\).
(b) State, with a reason, the number of real solutions to the equation $$x ^ { 2 } - 4 x + \frac { 1 } { x } = 0 .$$
SPS SPS SM 2020 October Q7
7. i. Sketch the curves \(y = \frac { 3 } { x ^ { 2 } }\) and \(y = x ^ { 2 } - 2\) on the axes provided below.
\includegraphics[max width=\textwidth, alt={}, center]{e1b41613-a703-4eb3-9760-7b47b1dad099-06_849_921_1683_644}
ii. In this question you must show detailed reasoning. Find the exact coordinates of the points of interception of the curves \(y = \frac { 3 } { x ^ { 2 } }\) and \(y = x ^ { 2 } - 2\).
iii. Hence, solve the inequality \(\frac { 3 } { x ^ { 2 } } \leq x ^ { 2 } - 2\), giving your answer in interval notation.
OCR Pure 1 2018 March Q4
4
  1. Sketch the curves \(y = \frac { 3 } { x ^ { 2 } }\) and \(y = x ^ { 2 } - 2\) on the axes provided in the Printed Answer Booklet.
  2. In this question you must show detailed reasoning. Find the exact coordinates of the points of intersection of the curves \(y = \frac { 3 } { x ^ { 2 } }\) and \(y = x ^ { 2 } - 2\).