tmua

2020 paper2

20 maths questions

Find the complete set of values of $k$ for which the line $y = x - 2$ crosses or touches the curve $y = x ^ { 2 } + k x + 2$
A $- 1 \leq k \leq 3$
B $- 3 \leq k \leq 5$
C $- 4 \leq k \leq 4$
D $k \leq - 1$ or $k \geq 3$
E $k \leq - 3$ or $k \geq 5$ F $k \leq - 4$ or $k \geq 4$
Q2 1 marks Reciprocal Trig & Identities View
Given that $\tan \theta = 2$ and $180 ^ { \circ } < \theta < 360 ^ { \circ }$, find the value of $\cos \theta$
A $\sqrt { 3 }$
B $- \sqrt { 3 }$
C $\frac { \sqrt { 3 } } { 2 }$
D $- \frac { \sqrt { 3 } } { 2 }$
E $\frac { \sqrt { 5 } } { 5 }$ F $- \frac { \sqrt { 5 } } { 5 }$ G $\frac { 2 \sqrt { 5 } } { 5 }$ H $- \frac { 2 \sqrt { 5 } } { 5 }$
Q3 1 marks Proof True/False Justification View
A student makes the following claim: For all integers $n$, the expression $4 \left( \frac { 9 n + 1 } { 2 } - \frac { 3 n - 1 } { 2 } \right)$ is divisible by 3 . Here is the student's argument:
$$\begin{aligned} 4 \left( \frac { 9 n + 1 } { 2 } - \frac { 3 n - 1 } { 2 } \right) & = 2 \left( 2 \left( \frac { 9 n + 1 } { 2 } - \frac { 3 n - 1 } { 2 } \right) \right) \\ & = 2 ( 9 n + 1 - 3 n - 1 ) \\ & = 2 ( 6 n ) \\ & = 12 n \\ & = 3 ( 4 n ) \end{aligned}$$
which is always a multiple of 3 .
So the expression $4 \left( \frac { 9 n + 1 } { 2 } - \frac { 3 n - 1 } { 2 } \right)$ is always divisible by 3 .
Which one of the following is true?
A The argument is correct.
B The argument is incorrect, and the first error occurs on line (I).
C The argument is incorrect, and the first error occurs on line (II).
D The argument is incorrect, and the first error occurs on line (III).
E The argument is incorrect, and the first error occurs on line (IV). F The argument is incorrect, and the first error occurs on line (V). G The argument is incorrect, and the first error occurs on line (VI).
Q4 1 marks Proof True/False Justification View
Consider the following statement: Every positive integer $N$ that is greater than 6 can be written as the sum of two non-prime integers that are greater than 1 .
Which of the following is/are counterexample(s) to this statement? I $\quad N = 5$ II $\quad N = 7$ III $N = 9$
A none of them
B I only
C II only
D III only
E I and II only F I and III only G II and III only H I, II and III
Q5 1 marks Exponential Functions MCQ on Function Properties View
Which one of the following shows the graph of
$$y = \frac { 2 ^ { x } } { 1 + 2 ^ { x } }$$
(Dotted lines indicate asymptotes.)
Q6 1 marks Indefinite & Definite Integrals Integral Equation with Symmetry or Substitution View
The function $\mathrm { f } ( x )$ is defined for all real values of $x$. Which of the following conditions on $\mathrm { f } ( x )$ is/are necessary to ensure that
$$\int _ { - 5 } ^ { 0 } \mathrm { f } ( x ) \mathrm { d } x = \int _ { 0 } ^ { 5 } \mathrm { f } ( x ) \mathrm { d } x$$
Condition I: $\quad \mathrm { f } ( x ) = \mathrm { f } ( - x ) $ for $- 5 \leq x \leq 5$ Condition II: $\mathrm { f } ( x ) = c$ for $- 5 \leq x \leq 5$, where $c$ is a constant Condition III: $\mathrm { f } ( x ) = - \mathrm { f } ( - x ) $ for $- 5 \leq x \leq 5$
A none of them
B I only
C II only
D III only
E I and II only F I and III only G II and III only H I, II and III
Q7 1 marks Proof View
Consider the following conditions on a parallelogram $P Q R S$, labelled anticlockwise:
I length of $P Q =$ length of $Q R$ II The diagonal $P R$ intersects the diagonal $Q S$ at right angles III $\angle P Q R = \angle Q R S$ Which of these conditions is/are individually sufficient for the parallelogram $P Q R S$ to be a square?
Q8 1 marks Proof True/False Justification View
A student is asked to prove whether the following statement (*) is true or false: (*) For all real numbers $a$ and $b , | a + b | < | a | + | b |$
The student's proof is as follows:
Statement (*) is false. A counterexample is $a = 3 , b = 4$, as $| 3 + 4 | = 7$ and $| 3 | + | 4 | = 7$, but $7 < 7$ is false.
Which of the following best describes the student's proof?
A The statement ( $*$ ) is true, and the student's proof is not correct.
B The statement (*) is false, but the student's proof is not correct: the counterexample is not valid.
C The statement (*) is false, but the student's proof is not correct: the student needs to give all the values of $a$ and $b$ where $| a + b | < | a | + | b |$ is false.
D The statement (*) is false, but the student's proof is not correct: the student should have instead stated that for all real numbers $a$ and $b , | a + b | \leq | a | + | b |$.
E The statement (*) is false, and the student's proof is fully correct.
Q9 1 marks Laws of Logarithms Simplify or Evaluate a Logarithmic Expression View
A student wishes to evaluate the function $\mathrm { f } ( x ) = x \sin x$, where $x$ is in radians, but has a calculator that only works in degrees.
What could the student type into their calculator to correctly evaluate $\mathrm { f } ( 4 )$ ?
A $( \pi \times 4 \div 180 ) \times \sin ( 4 )$
B $( \pi \times 4 \div 180 ) \times \sin ( \pi \times 4 \div 180 )$
C $4 \times \sin ( \pi \times 4 \div 180 )$
D $( 180 \times 4 \div \pi ) \times \sin ( 4 )$
E $\quad ( 180 \times 4 \div \pi ) \times \sin ( 180 \times 4 \div \pi )$ F $\quad 4 \times \sin ( 180 \times 4 \div \pi )$
The real numbers $a , b , c$ and $d$ satisfy both
$$0 < a + b < c + d$$
and
$$0 < a + c < b + d$$
Which of the following inequalities must be true? I $a < d$ II $b < c$ III $a + b + c + d > 0$
A none of them
B I only
C II only
D III only
E I and II only F I and III only G II and III only H I, II and III
Q11 1 marks Geometric Probability View
A spiral line is drawn as shown.
This spiral pattern continues indefinitely. Which one of the following points is not on the spiral line?
A $( 99,100 )$
B $( 99 , - 100 )$
C $( - 99,100 )$
D $( - 99 , - 100 )$
E $( 100,99 )$ F $( 100 , - 99 )$ G $( - 100,99 )$ H ( $- 100 , - 99$ )
Q12 1 marks Numerical integration Quadrature Error Bound Derivation View
Which one of $\mathbf { A } - \mathbf { F }$ correctly completes the following statement? Given that $a < b$, and $\mathrm { f } ( x ) > 0$ for all $x$ with $a < x < b$, the trapezium rule produces an overestimate for $\int _ { a } ^ { b } \mathrm { f } ( x ) \mathrm { d } x \ldots$
A ... if $\mathrm { f } ^ { \prime } ( x ) > 0$ and $\mathrm { f } ^ { \prime \prime } ( x ) < 0$ for all $x$ with $a < x < b$
B ... only if $\mathrm { f } ^ { \prime } ( x ) > 0$ and $\mathrm { f } ^ { \prime \prime } ( x ) < 0$ for all $x$ with $a < x < b$
C ... if and only if $\mathrm { f } ^ { \prime } ( x ) > 0$ and $\mathrm { f } ^ { \prime \prime } ( x ) < 0$ for all $x$ with $a < x < b$
D ... if $\mathrm { f } ^ { \prime } ( x ) < 0$ and $\mathrm { f } ^ { \prime \prime } ( x ) > 0$ for all $x$ with $a < x < b$
E $\ldots$ only if $\mathrm { f } ^ { \prime } ( x ) < 0$ and $\mathrm { f } ^ { \prime \prime } ( x ) > 0$ for all $x$ with $a < x < b$ F ... if and only if $\mathrm { f } ^ { \prime } ( x ) < 0$ and $\mathrm { f } ^ { \prime \prime } ( x ) > 0$ for all $x$ with $a < x < b$
Q13 1 marks Indefinite & Definite Integrals Integral Inequalities and Limit of Integral Sequences View
$\mathrm { f } ( x )$ is a function for which
$$\int _ { 0 } ^ { 3 } ( \mathrm { f } ( x ) ) ^ { 2 } \mathrm {~d} x + \int _ { 0 } ^ { 3 } \mathrm { f } ( x ) \mathrm { d } x = \int _ { 0 } ^ { 1 } \mathrm { f } ( x ) \mathrm { d } x$$
Which of the following claims about $\mathrm { f } ( x )$ is/are necessarily true? I $\mathrm { f } ( x ) \leq 0$ for some $x$ with $1 \leq x \leq 3$ II $\int _ { 0 } ^ { 3 } \mathrm { f } ( x ) \mathrm { d } x \leq \int _ { 0 } ^ { 1 } \mathrm { f } ( x ) \mathrm { d } x$
A neither of them
B I only
C II only
D I and II
Q14 1 marks Arithmetic Sequences and Series Optimization Involving an Arithmetic Sequence View
An arithmetic sequence $T$ has first term $a$ and common difference $d$, where $a$ and $d$ are non-zero integers.
Property P is:
For some positive integer $m$, the sum of the first $m$ terms of the sequence is equal to the sum of the first $2 m$ terms of the sequence.
For example, when $a = 11$ and $d = - 2$, the sequence $T$ has property P , because
$$11 + 9 + 7 + 5 = 11 + 9 + 7 + 5 + 3 + 1 + ( - 1 ) + ( - 3 )$$
i.e. the sum of the first 4 terms equals the sum of the first 8 terms. Which of the following statements is/are true? I For $T$ to have property P , it is sufficient that $a d < 0$. II For $T$ to have property P , it is necessary that $d$ is even.
A neither of them
B I only
C II only
D I and II
Q15 1 marks Standard trigonometric equations Solve trigonometric equation for solutions in an interval View
Which one of the following is a necessary and sufficient condition for
$$\sum _ { k = 1 } ^ { n } \sin \left( \frac { k \pi } { 3 } \right) = \frac { \sqrt { 3 } } { 2 }$$
to be true?
A $n = 1$
B $n$ is a multiple of 3
C $n$ is a multiple of 6
D $n$ is 1 more than a multiple of 3
E $n$ is 1 more than a multiple of 6 F $n$ is 1 more than a multiple of 6 or $n$ is 2 more than a multiple of 6
The Fundamental Theorem of Calculus (FTC) tells us that for any polynomial f :
$$\frac { \mathrm { d } } { \mathrm {~d} x } \left( \int _ { 0 } ^ { x } \mathrm { f } ( t ) \mathrm { d } t \right) = \mathrm { f } ( x )$$
A student calculates $\frac { \mathrm { d } } { \mathrm { d } x } \left( \int _ { x } ^ { 2 x } t ^ { 2 } \mathrm {~d} t \right)$ as follows: (I) $\quad \int _ { x } ^ { 2 x } t ^ { 2 } \mathrm {~d} t = \int _ { 0 } ^ { 2 x } t ^ { 2 } \mathrm {~d} t - \int _ { 0 } ^ { x } t ^ { 2 } \mathrm {~d} t$ (II) By FTC, $\frac { \mathrm { d } } { \mathrm { d } x } \left( \int _ { 0 } ^ { x } t ^ { 2 } \mathrm {~d} t \right) = x ^ { 2 }$ (III) By FTC, $\frac { \mathrm { d } } { \mathrm { d } x } \left( \int _ { 0 } ^ { 2 x } t ^ { 2 } \mathrm {~d} t \right) = ( 2 x ) ^ { 2 } = 4 x ^ { 2 }$ (IV) So $\frac { \mathrm { d } } { \mathrm { d } x } \left( \int _ { x } ^ { 2 x } t ^ { 2 } \mathrm {~d} t \right) = 4 x ^ { 2 } - x ^ { 2 }$ (V) giving $\frac { \mathrm { d } } { \mathrm { d } x } \left( \int _ { x } ^ { 2 x } t ^ { 2 } \mathrm {~d} t \right) = 3 x ^ { 2 }$
Which of the following best describes the student's calculation?
A The calculation is completely correct.
B The calculation is incorrect, and the first error occurs on line (I).
C The calculation is incorrect, and the first error occurs on line (II).
D The calculation is incorrect, and the first error occurs on line (III).
E The calculation is incorrect, and the first error occurs on line (IV). F The calculation is incorrect, and the first error occurs on line (V).
Q17 1 marks Measures of Location and Spread View
A set of six distinct integers is split into two sets of three. The first set of three integers has a mean of 10 and a median of 8 . The second set of three integers has a mean of 12 and a median of 9 . What is the smallest possible range of the set of all six integers?
A 8
B 10
C 11
D 12
E 14 F 15
Q18 1 marks Curve Sketching Multi-Statement Verification (Remarks/Options) View
In this question, $\mathrm { f } ( x ) = a x ^ { 3 } + b x ^ { 2 } + c x + d$ and $\mathrm { g } ( x ) = p x ^ { 3 } + q x ^ { 2 } + r x + s$ are cubic polynomials.
If $f ( x ) - g ( x ) > 0$ for every real $x$, which of the following is/are necessarily true?
I $a > p$ II if $b = q$ then $c = r$ III $d > s$
A none of them
B I only
C II only
D III only
E I and II only F I and III only G II and III only H I, II and III
Nine people are sitting in the squares of a 3 by 3 grid,one in each square,as shown. Two people are called neighbours if they are sitting in squares that share a side. (People in diagonally adjacent squares,which only have a point in common,are not called neighbours.)
Each of the nine people in the grid is either a truth-teller who always tells the truth, or a liar who always lies.
Every person in the grid says:'My neighbours are all liars'. Given only this information,what are the smallest number and the largest number of people who could be telling the truth?
$x$ is a real number and f is a function. Given that exactly one of the following statements is true, which one is it?
A $x \geq 0$ only if $\mathrm { f } ( x ) < 0$
B $x < 0$ if $\mathrm { f } ( x ) \geq 0$
C $\quad x \geq 0$ only if $\mathrm { f } ( x ) \geq 0$
D $\mathrm { f } ( x ) < 0$ if $x < 0$
E $\quad \mathrm { f } ( x ) \geq 0$ only if $x \geq 0$ F $\quad \mathrm { f } ( x ) \geq 0$ if and only if $x < 0$