OCR MEI C1 2007 January — Question 3 3 marks

Exam BoardOCR MEI
ModuleC1 (Core Mathematics 1)
Year2007
SessionJanuary
Marks3
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicSolving quadratics and applications
TypeRearranging formula - variable appears multiple times
DifficultyEasy -1.8 This is a linear rearrangement, not quadratic—simply collecting terms with 'a' and factoring gives a = 2c/(f-2). It's purely algebraic manipulation with no problem-solving required, easier than typical A-level questions which involve calculus or genuine quadratic solving.
Spec1.02c Simultaneous equations: two variables by elimination and substitution

3 Make \(a\) the subject of the equation $$2 a + 5 c = a f + 7 c$$

Question 3:
Simplify \((m^2-1)^2 - (m^2+1)^2\), showing your method.
Hence, given the right-angled triangle in Fig. 10, express \(p\) in terms of \(m\), simplifying your answer.
[4]
Fig. 10 shows a right-angled triangle with sides \(m^2+1\), \(m^2-1\), and \(p\).
Section B (36 marks)
Question 11:
There is an insert for use in this question.
The graph of \(y = x + \frac{1}{x}\) is shown on the insert. The lowest point on one branch is \((1, 2)\). The highest point on the other branch is \((-1, -2)\).
(i) Use the graph to solve the following equations, showing your method clearly.
(A) \(x + \frac{1}{x} = 4\) [2]
(B) \(2x + \frac{1}{x} = 4\) [4]
(ii) The equation \((x-1)^2 + y^2 = 4\) represents a circle. Find in exact form the coordinates of the points of intersection of this circle with the \(y\)-axis. [2]
(iii) State the radius and the coordinates of the centre of this circle. Explain how these can be used to deduce from the graph that this circle touches one branch of the curve \(y = x + \frac{1}{x}\) but does not intersect with the other. [4]
Question 3:

Simplify $(m^2-1)^2 - (m^2+1)^2$, showing your method.

Hence, given the right-angled triangle in Fig. 10, express $p$ in terms of $m$, simplifying your answer.

[4]

Fig. 10 shows a right-angled triangle with sides $m^2+1$, $m^2-1$, and $p$.

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Section B (36 marks)

Question 11:

There is an insert for use in this question.

The graph of $y = x + \frac{1}{x}$ is shown on the insert. The lowest point on one branch is $(1, 2)$. The highest point on the other branch is $(-1, -2)$.

(i) Use the graph to solve the following equations, showing your method clearly.

(A) $x + \frac{1}{x} = 4$ [2]

(B) $2x + \frac{1}{x} = 4$ [4]

(ii) The equation $(x-1)^2 + y^2 = 4$ represents a circle. Find in exact form the coordinates of the points of intersection of this circle with the $y$-axis. [2]

(iii) State the radius and the coordinates of the centre of this circle. Explain how these can be used to deduce from the graph that this circle touches one branch of the curve $y = x + \frac{1}{x}$ but does not intersect with the other. [4]
3 Make $a$ the subject of the equation

$$2 a + 5 c = a f + 7 c$$

\hfill \mbox{\textit{OCR MEI C1 2007 Q3 [3]}}