What is the solution to \(\abs{2 x+3}<5\) ?
- \(-4<x<1\)
- \(x<-4\) or \(x>1\)
- \(-1<x<4\)
- \(x<-1\) or \(x>4\)
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What is the solution to \(\abs{2 x+3}<5\) ?
\(A\)
\(\abs{2 x+3}<5\)
\(-5 < 2x+3 <5\)
\(-8< 2x < 2\)
\(-4<x<1\)
\(\Rightarrow A\)
A house has a reverse-cycle air conditioner which uses 2.5 kW of power for cooling and 3.2 kW of power for heating. The cost of electricity is 29 cents per kWh .
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a. \(\text{Cooling cost (6 hours )}\ = 6 \times 2.5 \times 0.29 = \$4.35\)
b. \(7.5\ \text{hours}\)
a. \(\text{Cooling cost (6 hours )}\ = 6 \times 2.5 \times 0.29 = \$4.35\)
b. \(\text{Let \(h\) = hours used per day}\)
\(\text{Cost per day}\ = h \times 3.2 \times 0.29\)
\(\text{Cost (92 days )}\ = 92 \times h \times 3.2 \times 0.29\)
\(\text{Find \(h\) when cost = \$640:}\)
| \(640\) | \(=92 \times h \times 3.2 \times 0.29\) | |
| \(h\) | \(=\dfrac{640}{92 \times 3.2 \times 0.29}=7.5\ \text{hours (1 d.p.)}\) |
The activities and corresponding durations in days for a project are shown in the network diagram.
\begin{array} {|c|c|}
\hline
\rule{0pt}{2.5ex} \text{Activity} \rule[-1ex]{0pt}{0pt} & \text{Immediate prerequisite(s)} \\
\hline
\rule{0pt}{2.5ex} B \rule[-1ex]{0pt}{0pt} & \\
\hline
\rule{0pt}{2.5ex} E \rule[-1ex]{0pt}{0pt} & \\
\hline
\rule{0pt}{2.5ex} F \rule[-1ex]{0pt}{0pt} & \\
\hline
\end{array}
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The duration of activity \( A \) is increased by 2. Does this affect the critical path for the project? Give a reason for your answer. (1 mark)
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a.
\begin{array} {|c|c|}
\hline
\rule{0pt}{2.5ex} \text{Activity} \rule[-1ex]{0pt}{0pt} & \text{Immediate prerequisite(s)} \\
\hline
\rule{0pt}{2.5ex} B \rule[-1ex]{0pt}{0pt} & \text{X} \\
\hline
\rule{0pt}{2.5ex} E \rule[-1ex]{0pt}{0pt} & C,D \\
\hline
\rule{0pt}{2.5ex} F \rule[-1ex]{0pt}{0pt} & E \\
\hline
\end{array}
b. \(\text{Critical Path:}\ BDEFH\)
\(\text{Minimum Duration}\ =4+5+5+7+5=26\ \text{days}\)
c. \(\text{If duration of activity \(A\) is increased by 2:}\)
\(\text{The critical path remains unchanged (EST of activity \(E\) remains = 9)}\)
a.
\begin{array} {|c|c|}
\hline
\rule{0pt}{2.5ex} \text{Activity} \rule[-1ex]{0pt}{0pt} & \text{Immediate prerequisite(s)} \\
\hline
\rule{0pt}{2.5ex} B \rule[-1ex]{0pt}{0pt} & \text{X} \\
\hline
\rule{0pt}{2.5ex} E \rule[-1ex]{0pt}{0pt} & C,D \\
\hline
\rule{0pt}{2.5ex} F \rule[-1ex]{0pt}{0pt} & E \\
\hline
\end{array}
b.
\(\text{Critical Path:}\ BDEFH\)
\(\text{Minimum Duration}\ =4+5+5+7+5=26\ \text{days}\)
c. \(\text{If duration of activity \(A\) is increased by 2:}\)
\(\text{The critical path remains unchanged (EST of activity \(E\) remains = 9)}\)
Paint is sold in two sizes at a local shop.
Mina needs to purchase 80 litres of paint.
Calculate the amount of money Mina will save by purchasing only ten-litre cans of paint rather than only four-litre cans of paint. (2 marks)
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\(\text{Savings}\ = $160\)
\(\text{Cost of 4 litre cans:}\)
\( C_1=\dfrac{80}{4} \times 90=$1800 \)
\(\text{Cost of 10 litre cans:}\)
\( C_2=\dfrac{80}{10} \times 205=$1640\)
\(\therefore\ \text{Savings}\ = 1800-1640 = $160\)
Which of the following is arranged from largest to smallest?
\(D\)
\(\text{Largest to smallest:}\)
\( 3.2 \times 10^{-1}, 6.2 \times 10^{-3}, 4.5 \times 10^{-4}\)
\(\Rightarrow D\)
Frankie takes four weeks of annual leave. His weekly pay is $350 and his annual leave loading is \( 17 \dfrac{1}{2} \)% of four weeks pay.
What is Frankie's total pay for this period of annual leave?
\(D\)
\(\text{4 weeks pay}\ = 4 \times 350 = $1400\)
\(\text{Annual leave loading}\ =17.5\% \times 1400 = $245\)
\(\text{Total pay}\ = 1400+245=$1645\)
\(\Rightarrow D\)
The network shows the distances, in kilometres, along a series of roads that connect towns.
What is the value of the largest weighted edge included in the minimum spanning tree for this network?
What is \( {\displaystyle \int x(3 x^2+1)^4 d x} \) ?
\( A \)
| \[ \int x(3x^2+1)^4 dx\] | \(=\dfrac{1}{5} \cdot \dfrac{1}{6x}x(3x^2+1)^5+C\) | |
| \(=\dfrac{1}{30}(3x^2+1)^5+C\) |
\( \Rightarrow A \)
NOTE: Integrating by the reverse chain rule only works if some form of the derivative is already present outside of the brackets.
The displacement `x` metres from the origin at time `t` seconds of a particle travelling in a straight line is given by
`x = t^3-4t^2 +5t + 6` when `t >= 0`
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i. `8\ text(ms)^(−1)`
ii. `1, 5/3\ text(s)`
i. `x =t^3-4t^2 +5t + 6`
`v = (dx)/(dt) = 3t^2-8t +5`
`text(When)\ t = 3,`
| `v` | `= 3 xx 3^2-8 · 3 +5` |
| `= 8\ text(ms)^(−1)` |
ii. `text(Particle is stationary when)\ \ v = 0`
| `3t^2-8t +5` | `= 0` |
| `3t^2-3t-5t+5` | `= 0` |
| `3t(t-1)-5(t-1)` | `= 0` |
| `(t-1)(3t-5)` | `= 0` |
| `t` | `= 1, 5/3\ text(s)` |
The point \(T\) is the peak of a mountain and the point \(O\) is directly below the mountain's peak. The point \(Y\) is due east of \(O\) and the angle of elevation of \(T\) from \(Y\) is 60°. The point \(F\) is 4 km south-west of \(Y\). The points \(O, Y\) and \(F\) are on level ground. The angle of elevation of \(T\) from \(F\) is 45°.
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a. \(\text{See Worked Solutions}\)
b. \(h=3.03 \ \text{km}\)
c. \(\text {Bearing of \(O\) from \(F\)}=021^{\circ} \)
a. \(\text{In}\ \triangle TOY:\)
| \(\tan 60^{\circ}\) | \(=\dfrac{h}{OY}\) | |
| \(OY\) | \(=\dfrac{h}{\tan 60^{\circ}}\) | \(=\dfrac{h}{\sqrt{3}}\) |
b. \(\text{In}\ \triangle TOF:\)
\(\tan 45^{\circ}=\dfrac{h}{OF} \ \Rightarrow \ OF=h\)
\(\text{Since \(Y\) is due east of \(O\) and \(F\) is south-west of \(Y\):}\)
\(\angle OYF =45^{\circ}\)
\(\text{Using cosine rule in} \ \triangle OYF:\)
| \(OY^2+YF^2-2 \times OY \times YF\, \cos 45^{\circ}\) | \(=OF^2\) |
| \(\left(\dfrac{h}{\sqrt{3}}\right)^2+4^2-2 \times \dfrac{h}{\sqrt{3}} \times 4 \times \dfrac{1}{\sqrt{2}}\) | \(=h^2\) |
| \(\dfrac{h^2}{3}+16-\dfrac{8}{\sqrt{6}} h\) | \(=h^2\) |
| \(\dfrac{2}{3} h^2+\dfrac{8}{\sqrt{6}} h-16\) | \(=0\) |
|
\(h\) |
\(=\dfrac{\dfrac{-8}{\sqrt{6}}+\sqrt{\frac{64}{6}+4 \times \frac{2}{3} \times 16}}{2 \times \frac{2}{3}}\ \ \ (h>0)\) |
| \(=3.0277 \ldots\) | |
| \(=3.03 \ \text{km (to 2 d.p.)}\) |
c. \(\text {Using sine rule in} \ \ \triangle OYF:\)
| \(\dfrac{\sin\angle FOY}{4}\) | \(=\dfrac{\sin 45^{\circ}}{3.03}\) | |
| \(\sin \angle F O Y\) | \(=\dfrac{4 \times \sin 45^{\circ}}{3.03}=0.93347\) | |
| \(\angle FOY\) | \(=180-\sin^{-1}(0.93347)=180-68.98 \ldots = 111^{\circ} \ \text{(angle is obtuse)}\) |
\(\angle FOS^{\prime}=111-90=21^{\circ}\)
\(\angle \text{N}^{\prime}FO=21^{\circ}(\text {alternate})\)
\(\therefore \ \text {Bearing of \(O\) from \(F\)}=021^{\circ} \)
The shaded region is bounded by the graph \(y=\left(\dfrac{1}{2}\right)^x\), the coordinate axes and \(x=2\).
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a. \(A\approx \dfrac{9}{8}\ \text{units}^2\)
| b. | \(\text{Area}\) | \(=\displaystyle \int_0^2\left(\frac{1}{2}\right)^x d x\) |
| \(=\left[-\dfrac{2^{-x}}{\ln 2}\right]_0^2\) | ||
| \(=-\dfrac{2^{-2}}{\ln 2}+\dfrac{1}{\ln 2}\) | ||
| \(=-\dfrac{1}{4 \ln 2}+\dfrac{1}{\ln 2}\) | ||
| \(=\dfrac{3}{4 \ln 2}\) |
c. \(\text{Trapezoidal estimate assumes a straight line (creating a trapezium)}\)
\(\text{between (0,1) and \((2,\dfrac{1}{4})\)}\)
\(\Rightarrow \ \text{Area using trap rule > Actual area}\)
| \(\dfrac{9}{8}\) | \(>\dfrac{3}{4 \ln 2}\) | |
| \(36\, \ln 2\) | \(>24\) | |
| \(\ln 2\) | \(>\dfrac{2}{3}\) | |
| \(e^{\small \dfrac{2}{3}}\) | \(>2\) | |
| \(e\) | \(>2^{\small \dfrac{3}{2}}\) | |
| \(e\) | \(>2 \sqrt{2}\) |
a.
\begin{array}{|c|c|c|c|}
\hline \ \ x \ \ & \ \ 0 \ \ & \ \ 1 \ \ & \ \ 2 \ \ \\
\hline y & 1 & \dfrac{1}{2} & \dfrac{1}{4} \\
\hline
\end{array}
| \(A\) | \(\approx \dfrac{h}{2}\left[1 \times 1+2 \times \dfrac{1}{2}+1 \times \dfrac{1}{4}\right]\) |
| \(\approx \dfrac{1}{2}\left(\dfrac{9}{4}\right)\) | |
| \(\approx \dfrac{9}{8}\ \text{units}^2\) |
| b. | \(\text{Area}\) | \(=\displaystyle \int_0^2\left(\frac{1}{2}\right)^x d x\) |
| \(=\left[-\dfrac{2^{-x}}{\ln 2}\right]_0^2\) | ||
| \(=-\dfrac{2^{-2}}{\ln 2}+\dfrac{1}{\ln 2}\) | ||
| \(=-\dfrac{1}{4 \ln 2}+\dfrac{1}{\ln 2}\) | ||
| \(=\dfrac{3}{4 \ln 2}\) |
c. \(\text{Trapezoidal estimate assumes a straight line (creating a trapezium)}\)
\(\text{between (0,1) and \((2,\dfrac{1}{4})\)}\)
\(\Rightarrow \ \text{Area using trap rule > Actual area}\)
| \(\dfrac{9}{8}\) | \(>\dfrac{3}{4 \ln 2}\) | |
| \(36\, \ln 2\) | \(>24\) | |
| \(\ln 2\) | \(>\dfrac{2}{3}\) | |
| \(e^{\small \dfrac{2}{3}}\) | \(>2\) | |
| \(e\) | \(>2^{\small \dfrac{3}{2}}\) | |
| \(e\) | \(>2 \sqrt{2}\) |
In a research study, participants were asked to record the number of minutes they spent watching television and the number of minutes they spent exercising each day over a period of 3 months. The averages for each participant were recorded and graphed.
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The equation of the least-squares regression line for this dataset is
\(y=64.3-0.7 x\)
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a. \(\text{Form: Linear}\)
\(\text{Direction: Negative}\)
b. \(\text{Slope}=-0.7\)
\(\text{This means that for each added minute of watching television per day, a participant, on average,}\)
\(\text{will exercise for 0.7 minutes less.}\)
\(y \text{-intercept}=64.3\)
\(\text{If someone watches no television, the LSRL predicts they will exercise for 64.3 minutes per day.}\)
c. \(\text{34.9 minutes}\)
d. \(\text{At} \ \ x=120\ \text{(2 hours),} \ \ y=64.3-0.7 \times 120=-19.7\)
\(\text{The model predicts a negative value for time spent exercising, which is not possible.}\)
a. \(\text{Form: Linear}\)
\(\text{Direction: Negative}\)
b. \(\text{Slope}=-0.7\)
\(\text{This means that for each added minute of watching television per day, a participant, on average,}\)
\(\text{will exercise for 0.7 minutes less.}\)
\(y \text{-intercept}=64.3\)
\(\text{If someone watches no television, the LSRL predicts they will exercise for 64.3 minutes per day.}\)
c. \(\text{At} \ \ x=42:\)
\(y=64.3-0.7 \times 42=34.9\)
\(\therefore \ \text{Jo is expected to exercise for 34.9 minutes}\)
d. \(\text{At} \ \ x=120\ \text{(2 hours),} \ \ y=64.3-0.7 \times 120=-19.7\)
\(\text{The model predicts a negative value for time spent exercising, which is not possible.}\)
The numbers, 75, \(p\), \(q\), 2025, form a geometric sequence.
Find the values of \(p\) and \(q\). (2 marks)
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\(p=225, \ q=675\)
\(a=75, \ 75r=p, \ 75r^2=q, \ 75r^3=2025\)
\(\text{Using}\ \ 75r^3=2025:\)
\(r=\sqrt[3]{\dfrac{2025}{75}}=3\)
\(p=75 \times 3 = 225\)
\(q=75 \times 3^{2}=675\)
Find the equation of the tangent to \(y=5 x^3-\dfrac{2}{x^2}-9\) at the point \((1,-6)\). (3 marks)
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\(y=19 x-25\)
\(y=5 x^3-2 x^{-2}-9\)
\(y^{\prime}=15 x^2+4 x^{-3} \)
\(\text{At} \ \ x=1:\)
\(y^{\prime}=15+4=19\)
\(\text{Equation of line} \ \ m=19 \ \ \text {through}\ \ (1,-6): \)
| \(y+6\) | \(=19(x-1)\) |
| \(y+6\) | \(=19 x-19\) |
| \(y\) | \(=19 x-25\) |
The graph of a quadratic function represented by the equation \(h=t^2-8 t+12\) is shown.
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a. \(\text{Turning point at} \ \ (4,-4)\)
b. \(t=8\)
a. \(\text{Axis of quadratic occurs when}\ \ t= \dfrac{2+6}{2} = 4\)
\(\text{At} \ \ t=4:\)
\(h=4^2-8 \times 4+12=-4\)
\(\therefore \ \text{Turning point at} \ \ (4,-4)\)
b. \(\text {When} \ \ h=12:\)
| \(t^2-8 t+12\) | \(=12\) |
| \(t(t-8)\) | \(=0\) |
\(\therefore \ \text{Other value:} \ \ t=8\)
The graph of a quadratic function represented by the equation \(h=t^2-8 t+12\) is shown.
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a. \(\text{Turning point at} \ \ (4,-4)\)
b. \(t=8\)
a. \(\text{Strategy 1 (no calculus)}\)
\(\text{Axis of quadratic occurs when}\ \ t= \dfrac{2+6}{2} = 4\)
\(\text{At} \ \ t=4:\)
\(h=4^2-8 \times 4+12=-4\)
\(\therefore \ \text{Turning point at} \ \ (4,-4)\)
\(\text{Strategy 2 (using calculus)}\)
\(h=t^2-8 t+12\)
\(h^{\prime}=2 t-8\)
\(\text{Find \(t\) when} \ \ h^{\prime}=0:\)
\(2 t-8=0 \ \Rightarrow \ t=4\)
b. \(\text {When} \ \ h=12:\)
| \(t^2-8 t+12\) | \(=12\) |
| \(t(t-8)\) | \(=0\) |
\(\therefore \ \text{Other value:} \ \ t=8\)
What is \(\displaystyle \int \frac{1}{\sqrt{x+5}} d x\) ?
\(B\)
| \(\displaystyle \int \frac{1}{\sqrt{x+5}}\ d x\) | \(=\displaystyle \int (x+5)^{-\frac{1}{2}}\ d x\) | |
| \(= 2 \sqrt{x+5}+C\) |
\(\Rightarrow B\)
What is the domain of the function \(y=\sqrt{6-x^2}\) ?
\(D\)
\(6-x^2 \geq 6\ \ \Rightarrow\ \ x^2 \leq 6\)
\(-\sqrt{6} \leq x \leq \sqrt{6} \)
\(\Rightarrow D\)
The probability distribution table for a discrete random variable \(X\) is shown.
\begin{array}{|c|c|}
\hline \quad \quad x \quad \quad & \quad P(X=x) \quad\\
\hline 1 & 0.4 \\
\hline 2 & 0.2 \\
\hline 3 & \\
\hline
\end{array}
What is the value of \(P(X=3)\) ?
\(B\)
\(\text{Probabilities sum to 1:}\)
\(0.4+0.2+P(X=3) = 1\ \ \Rightarrow\ \ P(X=3) = 0.4\)
\(\Rightarrow B\)
The displacement of a particle moving along the `x`-axis is given by
`x = 1/4t^4 -t^3 -1/2t^2 +3t,`
where `x` is the displacement from the origin in metres and `t` is the time in seconds, for `t >= 0`.
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i. `x = 1/4t^4 -t^3 -1/2t^2 +3t`
`v = (dx)/(dt) = t^3-3t^2-t+3`
`text(Find)\ \ v\ \ text(when)\ \ t = 0:`
| `v` | `= 0 -3(0) -0+ 3` |
| `= 3\ text(ms)^(-1)` |
ii. `text(Particle is stationary when)\ \ v = 0`
| `t^3-3t^2-t+3` | `=0` | |
| `t^2(t-3)-1(t-3)` | `=0` | |
| `(t-3)(t^2-1)` | `=0` | |
| `(t-3)(t-1)(t+1)` | `=0` |
`t = 1 or 3\ text(seconds), t >= 0`
iii. `a = (dv)/(dt) = 3t^2-6t-1`
`text(Find)\ \ t\ \ text(when)\ \ a = 4/3`
| `3t^2-6t-1` | `= 4/3` |
| `3t^2-6t-7/3` | `= 0` |
| `9t^2-18t-7` | `=0` |
| `(3t-7)(3t+1)` | `=0` |
| `t` | `=7/3`, `t >= 0` |
| `x(7/3)` | `= 1/4(7/3)^4 -(7/3)^3 -1/2(7/3)^2 +3(7/3)` |
| `= -329/324\ text(m)` |
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| a. `y` | `= x^2-5x+6` |
| `= (x-2)(x-3)` |
`text(Cuts)\ xtext(-axis at)\ \ x = 2\ \ text(or)\ \ x = 3`
`(dy)/(dx) = 2x-5`
`text(At)\ \ x = 2 \ => \ (dy)/(dx) = -1`
`T_1\ text(has)\ \ m = −1,\ text{through (2, 0)}`
| `y -0` | `= -1(x-2)` |
| `y` | `= -x+2` |
`text(At)\ \ x = 3 \ => \ (dy)/(dx) = 1`
`T_2\ text(has)\ \ m = 3,\ text{through (3, 0)}`
| `y -0` | `= 1(x-3)` |
| `y` | `= x -3` |
b. `text(Intersection occurs when:)`
| `-x+2` | `= x-3` |
| `2x` | `= 5` |
| `x` | `= 5/2` |
`y = 5/2 – 3 = −1/2`
`:.\ text(Intersection at)\ \ (5/2, −1/2)`
Find the equation of the tangent to the curve `y=x(3x+2)^2` at the point `(1,25)`. (3 marks)
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`y=55x-30`
| `y` | `=x(3x+2)^2` | |
| `dy/dx` | `=6x(3x+2) + (3x+2)^2` | |
| `=(3x+2)(9x+2)` |
`text{At}\ x=1\ \ =>\ \ dy/dx=(3(1)+2)(9(1)+2)=55`
`text{Find equation of line}\ \ m=55,\ text{through}\ (1,25)`
| `y-y_1` | `=m(x-x_1)` | |
| `y-25` | `=55(x-1)` | |
| `y` | `=55x-30` |
Find the gradient of the tangent to the curve `y = 2x^3-5x^2 + 4` at the point `(2, 0)`. (2 marks)
`text(Gradient = 2.)`
| `y` | `= 2x^3-5x^2 + 4` | |
| `dy/dx` | `= 6x^2-10x` | |
`text(At)\ x = 2:`
`dy/dx= 6(2)^2-10(2)=24-20=4`
`:.\ text(Gradient of tangent at)\ (2, 0) = 4.`
Differentiate `(4x + 3)/(3x-4)`. (2 marks)
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`-25/(3x-4)^2`
`text(Using quotient rule:)`
| `u=4x+3,` | `v=3x-4` | |
| `u^{′} = 4,` | `v^{′} = 3` | |
| `y^{′}` | `= (u^{′} v-v^{′} u)/v^2` |
| `= (4(3x-4)-3(4x+3))/(3x-4)^2` | |
| `= (12x-16-12x-9)/(3x-4)^2` | |
| `= -25/(3x-4)^2` |
Find `f^{′}(x)`, where `f(x) = (2x^2-3x)/(2-x).` (2 marks)
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`((x-3) (x + 1))/(x-1)^2`
`f(x) = (2x^2-3x)/(2-x)`
`text(Using the quotient rule:)`
| `u` | `= 2x^2-3x` | `\ \ \ \ \ \ v` | `= 2-x` |
| `u^{′}` | `= 4x-3` | `\ \ \ \ \ \ v^{′}` | `= -1` |
| `f^{′}(x)` | `= (u^{′} v-uv^{′})/v^2` |
| `= ((4x-3)(2-x)-(2x^2-3x) xx -1)/(2-x)^2` | |
| `= (-2x^2 + 8x-6)/(x-2)^2` | |
| `= (-2(x^2-4x+3)/(x-2)^2` | |
| `= (-2(x-3) (x-1))/(x-2)^2` |
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| i. | `f(x)` | `= 2x^2 + 5x` |
| `f^{′}(x)` | `= lim_(h->0) (f(x + h)-f(x))/h` | |
| `= lim_(h->0) ((2(x + h)^2 +5(x + h))-(2x^2+5x))/h` | ||
| `= lim_(h->0)(2x^2 + 4xh + 2h^2+5x+5h-2x^2-5x)/h` | ||
| `= lim_(h->0)(4xh + 2h^2+5h)/h` | ||
| `= lim_(h->0)(h(4x+5 +2h))/h` |
`:.\ y^{′} = 4x+5`
ii. `text(When)\ \ x = 1, y = 7`
`y^{′} = 4+5 = 9`
| `:. y-7` | `= 9(x-1)` |
| `y` | `= 9x-2` |
A geochemist analyzes a rock sample and finds it contains 15 600 kg of ore. Chemical analysis shows that the ore contains 3.8% w/w of chromium metal.
Calculate the mass of chromium in the rock sample. Express your answer in scientific notation. (2 marks)
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\(5.93 \times 10^2\ \text{kg}\)
| Mass of chromium | \(= 3.8\% \times 15\,600\ \text{kg}\) | |
| \(=0.038 \times 15\,600\ \text{kg}\) | ||
| \(=5.93 \times 10^2\ \text{kg}\) |
Which statement about the periodic table is correct?
\(B\)
\(\Rightarrow B\)
The formula for the sulfate ion is \(\ce{SO4^2-}\). What is the formula for aluminium sulfate?
\(D\)
\(\Rightarrow D\)
Which row of the table correctly identifies a typical physical property of a metal element and a typical physical property of a non-metal element?
\begin{align*}
\begin{array}{l}
\rule{0pt}{2.5ex} \ \rule[-1ex]{0pt}{0pt}& \\
\rule{0pt}{2.5ex}\textbf{A.}\rule[-1ex]{0pt}{0pt}\\
\rule{0pt}{2.5ex}\textbf{B.}\rule[-1ex]{0pt}{0pt}\\
\rule{0pt}{2.5ex}\textbf{C.}\rule[-1ex]{0pt}{0pt}\\
\rule{0pt}{2.5ex}\textbf{D.}\rule[-1ex]{0pt}{0pt}\\
\end{array}
\begin{array}{|c|c|}
\hline
\rule{0pt}{2.5ex}\text{Physical property of metal}\rule[-1ex]{0pt}{0pt}& \text{Physical property of non-metal} \\
\hline
\rule{0pt}{2.5ex}\text{Good conductor of electricity}\rule[-1ex]{0pt}{0pt}&\text{Brittle}\\
\hline
\rule{0pt}{2.5ex}\text{Poor conductor of electricity}\rule[-1ex]{0pt}{0pt}& \text{Malleable}\\
\hline
\rule{0pt}{2.5ex}\text{Dull appearance}\rule[-1ex]{0pt}{0pt}& \text{High density} \\
\hline
\rule{0pt}{2.5ex}\text{Low melting point}\rule[-1ex]{0pt}{0pt}& \text{Lustrous} \\
\hline
\end{array}
\end{align*}
\(A\)
\(\Rightarrow A\)
Which of the following techniques would be used to separate a mixture of oil and water?
\(C\)
\(\Rightarrow C\)
Which of the following lists contains only metals?
\(A\)
\(\Rightarrow A\)
What is the formula of magnesium nitride?
\(C\)
\(\Rightarrow C\)
Radon-222 has a half-life of 3.8 days. How long will it take for a 64.0 g sample to decay to 4.00 g?
\(C\)
\(\Rightarrow C\)
Which of the following pairs represents isotopes of the same element?
\(A\)
\(\Rightarrow A\)
Thorium exists in several isotopic forms. The existence of these isotopes can be shown by placing a thorium sample in a mass spectrometer, in which atoms are vaporised, electrically charged, and the ratio of the mass/charge for each is compared.
A mass spectrogram of thorium is shown below. The mass number is displayed on the x-axis and the % abundance on the y-axis.
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a. \(Z=90\)
b. \(\ce{^228_90Th, ^230_90Th, ^232_90Th}\).
c. \(232.0\)
d. \(\ce{^232_90Th -> ^228_88Ra + ^4_2He}\)
a. \(Z = 90\) (atomic number)
b. \(\ce{^228_90Th, ^230_90Th, ^232_90Th}\).
| c. | \(M\) | \(=\dfrac{(228 \times 0.02) + (230 \times 0.8) + (232 \times 99.18)}{100}\) |
| \(=231.98\) | ||
| \(=232.0\ \text{(4 sig.fig)}\) |
d. Thorium-232 undergoes alpha decay:
\(\ce{^232_90Th -> ^228_88Ra + ^4_2He}\)
The concentration of an iron supplement is 250 mg / 5 mL. A patient is prescribed 1500 mg of the supplement.
How much medication should be given to the patient?
`C`
`text(Volume required)`
`= 1500/250 xx 5`
`= 30\ text(mL)`
`=> C`
Consider the elements in Group 1 of the periodic table.
What is the general trend in the first ionisation energy of these elements as you move down the group?
\(B\)
\(\Rightarrow B\)
Dana, Eden and Flynn are the first three players in the school basketball team. In a recent game, Dana scored 24 points, Eden scored 18 points and Flynn scored 30 points.
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| a. | `D:E:F` | `= 24:18:30` |
| `= 4:3:5` |
| b. | `text(Total points by)\ D,E,F` | `= 24 + 18 + 30` |
| `= 72` |
| `text(Let)\ P` | `=\ text(team points)` |
| `P/72` | `= 20/9` |
| `:. P` | `= (20 xx 72)/9` |
| `= 160\ text(points)` |
A population of Tasmanian devils, `D`, is to be modelled using the function `D = 650 (0.8)^t`, where `t` is the time in years.
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a. `650`
b. `416`
c. `text{See Worked Solutions}`
The table below contains data with reference to four common metals.
\begin{array} {|l|c|c|c|c|}
\hline \text{Metal} & \ce{Al} & \ce{Zn} & \ce{Sn} & \ce{Pb} \\
\hline \text{Z} & 13 & 30 & 50 & 82\\
\hline \text{A} & 26.98 & 65.38 & 118.7 & 207.2 \\
\hline \text{Melting point } (^{\circ}\text{C}) & 660 & 420 & 232 & 327 \\
\hline \text{Boiling point } (^{\circ}\text{C}) & 2470 & 907 & 2602 & 1749 \\
\hline
\end{array}
Which element remains a liquid over the greatest temperature range?
\(C\)
\(\ce{Al}: \ 2470-660= 1810^{\circ}\text{C}\)
\(\ce{Zn}: \ 907-420= 487^{\circ}\text{C}\)
\(\ce{Sn}: \ 2602-232= 2370^{\circ}\text{C}\)
\(\ce{Pb}: \ 1749-327= 1422^{\circ}\text{C}\)
\(\Rightarrow C\)
Rice is sold in four different sized packets. Which is the best buy?
`D`
\(\text{Price per kilogram}\)
\(\text{250 g:}\ 1.10 \times 4 = $4.40 \)
\(\text{500 g:}\ 2.00 \times 2 = $4.00 \)
\(\text{1 kg:}\ $3.80 \)
\(\text{2 kg:}\ 7.40\ ÷\ 2 = $3.70 \)
\(\text{Best buy is 2 kg at \$3.70/kg.}\)
\(\Rightarrow D\)
An old air conditioner uses 2.8 kW of electricity per hour. A new air conditioner uses 1.2 kW per hour. How much electricity is saved each year if the air conditioner runs for 5 hours per day for 200 days using the new model?
\(B\)
\(\text{Electricity used by old air conditioner}\ = 2.8 \times 5 \times 200 = 2800\ \text{kWh}\)
\(\text{Electricity used by new air conditioner}\ = 1.2 \times 5 \times 200 = 1200\ \text{kWh}\)
\(\therefore\ \text{Electricity saved} = 2800-1200 = 1600\ \text{kWh}\)
\(\Rightarrow B\)
An old dishwasher uses 45 L of water per cycle. A new dishwasher uses 15 L per cycle. How much water is saved each year if three cycles are run each week using the new dishwasher?
\(C\)
\(\text{Water used by old dishwasher}\ = 45 \times 3 \times 52 = 7020\ \text{L}\)
\(\text{Water used by new dishwasher}\ = 15 \times 3 \times 52 = 2340\ \text{L}\)
\(\text{Water saved}\ = 7020-2340 = 4680\ \text{L}\)
\(\Rightarrow C\)
A fitness professional designs different programs for two clients with similar fitness goals but different assessment results. One client shows strong upper body strength but poor cardiovascular endurance, while the other demonstrates good aerobic capacity but limited muscular strength. This approach primarily demonstrates which principle of assessment-based program development?
\(B\)
Other Options:
Why is personalisation essential when developing training programs for recreational participants? (3 marks)
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A recreational client wants to improve cardiovascular fitness but expresses strong dislike for running. Based on exercise assessment principles, which approach would be most appropriate for program development?
\(B\)
Other Options:
Describe how equipment innovations in assistive technology enhance performance for athletes with disability. In your answer, give two specific examples. (4 marks)
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Outline how wearable technology enhances performance monitoring for endurance athletes. (3 marks)
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Describe the key components involved in conducting a comprehensive exercise assessment. (3 marks)
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A fitness professional conducts a Rockport 1.6-kilometre walk test with a sedentary client before designing their exercise program. This assessment primarily serves which fundamental purpose?
\(A\)
Other Options:
What is the primary purpose of GPS technology in sport performance?
\(D\)
Other options:
Which of the following best describes the role of virtual reality (VR) in athlete training?
\(A\)
Other options:
A marathon runner completes a 42km race in hot conditions. Outline TWO physiological recovery strategies that would be most beneficial for this athlete immediately post-race. (3 marks)
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Recovery 1: Cool-down (10-15 minutes)
Cold water immersion (10-15°C for 10-15 minutes)
Recovery 1: Cool-down (10-15 minutes)
Cold water immersion (10-15°C for 10-15 minutes)
Describe the key features of a games-centred approach to tactical development in team sports. (3 marks)
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A basketball coach uses 3-on-3 half-court games during training to develop tactical awareness. This approach demonstrates which key principle of tactical development?
\(B\)
Other Options:
A netball team has several tall players but lacks speed and agility. Which tactical approach would best utilise their strengths while minimising their weaknesses?
\(B\)
Other Options:
Describe how wind conditions can affect strategies and tactics in both individual and group sports. (3 marks)
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