Let , whereand .
Calculate the exact value of .
Give your answer from part (a) correct to
Nina estimates the value of to be 2.
Calculate the percentage error in Nina's estimate.
Did this page help you?
Let , whereand .
Calculate the exact value of .
How did you do?
Give your answer from part (a) correct to
How did you do?
Nina estimates the value of to be 2.
Calculate the percentage error in Nina's estimate.
How did you do?
Did this page help you?
A pharmacy sells face masks in a variety of sizes. Their sales over a week are recorded in the table below:
Kids | Adults | |||||
Size | Small | Large | S | M | L | XL |
Frequency | 29 | 4 | 8 | 24 | 15 | 4 |
How did you do?
Did this page help you?
A coffee scoop is made out of 2 mm thick stainless steel. It is in the shape of a hemisphere and has an outer diameter of 3.8 cm.
Show that the outer surface area of the scoop is .
How did you do?
Calculate the volume of coffee that the scoop can hold, in cm3.
How did you do?
The density of the coffee when compacted in the scoop is 0.825 g/cm3. A single bag of ground coffee beans contains 350 g and costs $16.
Calculate the cost per scoop of ground coffee.
How did you do?
Did this page help you?
The total cost, , in New Zealand dollars (NZD), of a premium gym membership at Cityfitness can be modelled by the function
where is the time in weeks.
Calculate the cost of the gym membership for a year. Give your answer correct to 2 decimal places.
How did you do?
Find the number of weeks it takes for the total cost to exceed 2000 NZD.
How did you do?
At Les Mills the initial payment is 20 NZD lower than Cityfitness, however the weekly cost is 8.51 NZD higher than Cityfitness
Write a cost function for a gym membership at Les Mills using an appropriate model.
How did you do?
Calculate how many weeks it will take for the cost of a Les Mills gym membership be more than the cost of a Cityfitness gym membership.
How did you do?
Did this page help you?
A town is built in a rectangular area bounded by the lines y=-2, y=10, x = —4 and x = 10 as shown on the Voronoi diagram below.
Each horizontal and vertical unit on the grid below represents 1 km.
Points A(—2, 0), B(4, 8) and C(8, 0) represent the locations of first aid responders in the town.
Calculate the area for which the first aid responder at C has responsibility.
How did you do?
A new station is due to open at D(8, 2) and as such the Voronoi diagram will need to be adjusted.
How did you do?
Did this page help you?
An environmental organisation is trying to establish if altitude affects the growth of pine needles. A number of needles have been taken from trees at both high and low altitudes and their lengths, in inches, recorded. The results are shown in the table below.
Low altitude | 6.1 | 8.2 | 7.7 | 8.0 | 11.9 | 6.9 | 7.5 | 7.1 | 8.1 |
High altitude | 7.4 | 7.9 | 8.3 | 6.6 | 9.5 | 7.9 | 8.2 | 8.1 | 8.5 |
Perform a -test to compare the mean lengths of the pine needles.
Write down the null and alternative hypotheses.
How did you do?
State whether this is a one-tailed test or a two-tailed test.
How did you do?
Perform a -test at the 10% significance level. Write down the -value.
How did you do?
Write down the conclusion of the test. Give a reason for your answer.
How did you do?
Did this page help you?
The temperature, , of a cake, in degrees Celsius, , can be modelled by the function
where is a constant and is the time, in minutes, since the cake was taken out of the oven.
In the context of this model, state what the value of 18 represents.
How did you do?
The cake was 180°C when it was taken out of the oven.
Find the value of .
How did you do?
Find the temperature of the cake half an hour after being taken out of the oven.
How did you do?
Did this page help you?
Ben and Sam are both cyclists competing in a 22.5 km race at the Herne Hill Velodrome in London, England. One lap of the velodrome is 450 m.
Ben takes a total of 42 minutes to complete the race.
Calculate Ben's mean lap time in seconds.
How did you do?
Given that each of Ben's laps took him 1% longer to complete than the previous one, calculate how long it took him (in seconds) to complete his first and last laps.
How did you do?
Sam completes the first lap in 45 seconds and takes 0.2 seconds longer per lap.
Determine who completed the race the first out of Ben and Sam. Justify your answer.
How did you do?
Did this page help you?
The diagram below shows the triangular sail of a windsurfing board, , with a horizontal boom . m and makes an angle of 18° to the vertical. m and .
Find the area of the whole sail.
How did you do?
Calculate the length of the boom PC.
How did you do?
Did this page help you?
Frank plays a game involving a biased six-sided die.
The faces of the die are numbered to .
The score of the game, , is the number which lands face up after the die is rolled.
The following table shows the probability distribution for .
Score , | ||||||
Calculate the exact value of .
How did you do?
Frank plays the game once.
Calculate the expected score.
How did you do?
Did this page help you?
Consider the function .
Sketch the graph of the function , labelling the and intercepts.
How did you do?
Find
How did you do?
Did this page help you?
The volume of a sphere of radius is given by the formula .
Find .
How did you do?
Find the rate of change of the volume with respect to the radius when
Give your answer in terms of .
How did you do?
Show that is an increasing function for all relevant values of
How did you do?
Did this page help you?
The following diagram shows an arch that is 4.5 m tall and 3 m wide. The arch crosses the -axis at the origin, , and at point , and its vertex is at point . The arch may be represented by a curve with an equation of the form , where all units are measured in metres.
Find
How did you do?
Find the cross-sectional area under the arch.
How did you do?
Did this page help you?