CAIE
FP1
2011
November
Q2
2 The position vectors of points \(A , B , C\), relative to the origin \(O\), are \(\mathbf { a } , \mathbf { b } , \mathbf { c }\), where
$$\mathbf { a } = 3 \mathbf { i } + 2 \mathbf { j } - \mathbf { k } , \quad \mathbf { b } = 4 \mathbf { i } - 3 \mathbf { j } + 2 \mathbf { k } , \quad \mathbf { c } = 3 \mathbf { i } - \mathbf { j } - \mathbf { k }$$
Find \(\mathbf { a } \times \mathbf { b }\) and deduce the area of the triangle \(O A B\).
Hence find the volume of the tetrahedron \(O A B C\), given that the volume of a tetrahedron is \(\frac { 1 } { 3 } \times\) area of base × perpendicular height.
CAIE
FP1
2011
November
Q7
7 The curve \(C\) has equation \(y = \frac { x ^ { 2 } + p x + 1 } { x - 2 }\), where \(p\) is a constant. Given that \(C\) has two asymptotes, find the equation of each asymptote.
Find the set of values of \(p\) for which \(C\) has two distinct turning points.
Sketch \(C\) in the case \(p = - 1\). Your sketch should indicate the coordinates of any intersections with the axes, but need not show the coordinates of any turning points.
CAIE
FP1
2011
November
Q8
8 The vector \(\mathbf { e }\) is an eigenvector of the matrix \(\mathbf { A }\), with corresponding eigenvalue \(\lambda\), and is also an eigenvector of the matrix \(\mathbf { B }\), with corresponding eigenvalue \(\mu\). Show that \(\mathbf { e }\) is an eigenvector of the matrix \(\mathbf { A B }\) with corresponding eigenvalue \(\lambda \mu\).
State the eigenvalues of the matrix \(\mathbf { C }\), where
$$\mathbf { C } = \left( \begin{array} { r r r }
- 1 & - 1 & 3 \\
0 & 1 & 2 \\
0 & 0 & 2
\end{array} \right) ,$$
and find corresponding eigenvectors.
Show that \(\left( \begin{array} { l } 1 \\ 6 \\ 3 \end{array} \right)\) is an eigenvector of the matrix \(\mathbf { D }\), where
$$\mathbf { D } = \left( \begin{array} { r r r }
1 & - 1 & 1 \\
- 6 & - 3 & 4 \\
- 9 & - 3 & 7
\end{array} \right) ,$$
and state the corresponding eigenvalue.
Hence state an eigenvector of the matrix CD and give the corresponding eigenvalue.
CAIE
FP1
2014
November
Q3
3 It is given that \(u _ { r } = r \times r !\) for \(r = 1,2,3 , \ldots\). Let \(S _ { n } = u _ { 1 } + u _ { 2 } + u _ { 3 } + \ldots + u _ { n }\). Write down the values of
$$2 ! - S _ { 1 } , \quad 3 ! - S _ { 2 } , \quad 4 ! - S _ { 3 } , \quad 5 ! - S _ { 4 }$$
Conjecture a formula for \(S _ { n }\).
Prove, by mathematical induction, a formula for \(S _ { n }\), for all positive integers \(n\).
CAIE
FP1
2014
November
Q7
7 Let \(I _ { n } = \int _ { 0 } ^ { 1 } ( 1 - x ) ^ { n } \mathrm { e } ^ { x } \mathrm {~d} x\). Show that, for all positive integers \(n\),
$$I _ { n } = n I _ { n - 1 } - 1$$
Find the exact value of \(I _ { 4 }\).
By considering the area of the region enclosed by the \(x\)-axis, the \(y\)-axis and the curve with equation \(y = ( 1 - x ) ^ { 4 } \mathrm { e } ^ { x }\) in the interval \(0 \leqslant x \leqslant 1\), show that
$$\frac { 65 } { 24 } < \mathrm { e } < \frac { 11 } { 4 }$$
CAIE
FP1
2014
November
Q8
8 A circle has polar equation \(r = a\), for \(0 \leqslant \theta < 2 \pi\), and a cardioid has polar equation \(r = a ( 1 - \cos \theta )\), for \(0 \leqslant \theta < 2 \pi\), where \(a\) is a positive constant. Draw sketches of the circle and the cardioid on the same diagram.
Write down the polar coordinates of the points of intersection of the circle and the cardioid.
Show that the area of the region that is both inside the circle and inside the cardioid is
$$\left( \frac { 5 } { 4 } \pi - 2 \right) a ^ { 2 }$$