2007 H2 Math Paper 1 Answers

1
x<3,2<x<1 or x>7.{x < - 3, \, -2 < x < -1 \, \textrm{ or } x > 7.}
2
(a)
fg{fg} does not exist because Rg=[0,]⊈(,3)(3,)=Df.R_g = {\left[ 0, \infty \right]} \not \subseteq {\left( -\infty , 3 \right) \cup \left( 3 , \infty \right)} = D_f.
gf:x(1x3)2,for xR,x3.\displaystyle gf : x \mapsto \left( \frac{1}{ x - 3 } \right)^2, \quad \allowbreak {\textrm{for } x \in \mathbb{R}, x \neq 3.}
(b)
f1(x)=1x+3.{\displaystyle f^{-1}(x) = \frac{1}{ x } + 3.}
Df1=Rf=(,0)(0,).{\displaystyle D_{ f^{-1} } = R_f = \left( -\infty, 0 \right) \cup \left( 0, \infty \right).}
3
z=1+2i.{z = - 1 + 2 \mathrm{i}.}
4
(a)
y=23+43e34x.{y = \frac{2}{3} + \frac{4}{3} \mathrm{e}^{- \frac{3}{4} x}.}
(b)
y23.{y \to \frac{2}{3}.}
5
y=2+3x+2{y = 2 + \frac{ 3 }{ x + 2 }}
Transformation 1: Translate by 2 units in the negative x{x}-axis direction.
Transformation 2: Scale by a factor of 3{3} parallel to the y{y}-axis.
Transformation 3: Translate by 2 units in the positive y{y}-axis direction.
6
(b)
13(4i+2j+5k){\frac{1}{3} ( 4 \mathbf{i} + 2 \mathbf{j} + 5 \mathbf{k} )}
(c)
35{\sqrt{35}}
7
(b)
k=64.{k = 64.}
(c)
z6+64=(z223z+4)(z2+23z+4)(z2+4).{z^6 + 64} = {(z^2 - 2 \sqrt{3} z + 4)}\allowbreak{(z^2 + 2 \sqrt{3} z + 4)}{(z^2 + 4)}.
8
(a)
(52,32,112).{\left( \frac{5}{2} , \frac{3}{2} , \frac{11}{2} \right).}
(b)
78.8.{78.8^{\circ}.}
(c)
4714 units.{\frac{4}{7} \sqrt{14}\textrm{ units}.}
9
(a)
π(12e1012e824e5+18e4+183) units3.\pi \left( \frac{1}{2} \mathrm{e}^{10} - \frac{1}{2} \mathrm{e}^{8} - 24 \mathrm{e}^{5} + 18 \mathrm{e}^{4} + 183 \right) \allowbreak \textrm{ units}^3.
(b)
α=0.619,β=1.512.{\alpha = 0.619, \, \beta = 1.512.}
(c)
0.619<x<1.512.{0.619 < x < 1.512.}
(d)
0.18 units2{0.18\textrm{ units}^2}
10
(b)
The geometric series is convergent because 1<r=23<1.{-1 < r = \frac{2}{3} < 1.}
S=3a.{S_\infty = 3 a.}
(c)
{nZ:6n13}.{\{ n \in \mathbb{Z}: 6 \leq n \leq 13 \}.}
11
25 units2.{\frac{2}{5} \textrm{ units}^2.}

As questions 7 and 9 are no longer in the current syllabus, the answers provided to those (which are for a modified version of the questions) should be ignored.
The actual questions are the copyright of UCLES and MOE. These answers are my own and any errors therein are mine alone.
To practice on a variation of this paper to further reinforce your concepts, head over to 2007 paper 1 variant.