CAIE P1 (Pure Mathematics 1) 2003 June

1 Find the value of the coefficient of \(\frac { 1 } { x }\) in the expansion of \(\left( 2 x - \frac { 1 } { x } \right) ^ { 5 }\).

2 Find all the values of \(x\) in the interval \(0 ^ { \circ } \leqslant x \leqslant 180 ^ { \circ }\) which satisfy the equation \(\sin 3 x + 2 \cos 3 x = 0\).

3

1. Differentiate \(4 x + \frac { 6 } { x ^ { 2 } }\) with respect to \(x\).
2. Find \(\int \left( 4 x + \frac { 6 } { x ^ { 2 } } \right) \mathrm { d } x\).

4 In an arithmetic progression, the 1 st term is - 10 , the 15th term is 11 and the last term is 41 . Find the sum of all the terms in the progression.

5 The function f is defined by \(\mathrm { f } : x \mapsto a x + b\), for \(x \in \mathbb { R }\), where \(a\) and \(b\) are constants. It is given that \(f ( 2 ) = 1\) and \(f ( 5 ) = 7\).

1. Find the values of \(a\) and \(b\).
2. Solve the equation \(\operatorname { ff } ( x ) = 0\).

6

1. Sketch the graph of the curve \(y = 3 \sin x\), for \(- \pi \leqslant x \leqslant \pi\). The straight line \(y = k x\), where \(k\) is a constant, passes through the maximum point of this curve for \(- \pi \leqslant x \leqslant \pi\).
2. Find the value of \(k\) in terms of \(\pi\).
3. State the coordinates of the other point, apart from the origin, where the line and the curve intersect.

7 The line \(L _ { 1 }\) has equation \(2 x + y = 8\). The line \(L _ { 2 }\) passes through the point \(A ( 7,4 )\) and is perpendicular to \(L _ { 1 }\).

1. Find the equation of \(L _ { 2 }\).
2. Given that the lines \(L _ { 1 }\) and \(L _ { 2 }\) intersect at the point \(B\), find the length of \(A B\).

8 The points \(A , B , C\) and \(D\) have position vectors \(3 \mathbf { i } + 2 \mathbf { k } , 2 \mathbf { i } - 2 \mathbf { j } + 5 \mathbf { k } , 2 \mathbf { j } + 7 \mathbf { k }\) and \(- 2 \mathbf { i } + 10 \mathbf { j } + 7 \mathbf { k }\) respectively.

1. Use a scalar product to show that \(B A\) and \(B C\) are perpendicular.
2. Show that \(B C\) and \(A D\) are parallel and find the ratio of the length of \(B C\) to the length of \(A D\).

9 \includegraphics[max width=\textwidth, alt={}, center]{8214ccb9-0894-4c3c-a8d9-d8f8749fdbe1-3_321_636_267_758} The diagram shows a semicircle \(A B C\) with centre \(O\) and radius 8 cm . Angle \(A O B = \theta\) radians.

1. In the case where \(\theta = 1\), calculate the area of the sector BOC.
2. Find the value of \(\theta\) for which the perimeter of sector \(A O B\) is one half of the perimeter of sector BOC.
3. In the case where \(\theta = \frac { 1 } { 3 } \pi\), show that the exact length of the perimeter of triangle \(A B C\) is \(( 24 + 8 \sqrt { } 3 ) \mathrm { cm }\).

10 The equation of a curve is \(y = \sqrt { } ( 5 x + 4 )\).

1. Calculate the gradient of the curve at the point where \(x = 1\).
2. A point with coordinates \(( x , y )\) moves along the curve in such a way that the rate of increase of \(x\) has the constant value 0.03 units per second. Find the rate of increase of \(y\) at the instant when \(x = 1\).
3. Find the area enclosed by the curve, the \(x\)-axis, the \(y\)-axis and the line \(x = 1\).

11 The equation of a curve is \(y = 8 x - x ^ { 2 }\).

1. Express \(8 x - x ^ { 2 }\) in the form \(a - ( x + b ) ^ { 2 }\), stating the numerical values of \(a\) and \(b\).
2. Hence, or otherwise, find the coordinates of the stationary point of the curve.
3. Find the set of values of \(x\) for which \(y \geqslant - 20\). The function g is defined by \(\mathrm { g } : x \mapsto 8 x - x ^ { 2 }\), for \(x \geqslant 4\).
4. State the domain and range of \(\mathrm { g } ^ { - 1 }\).
5. Find an expression, in terms of \(x\), for \(\mathrm { g } ^ { - 1 } ( x )\).