9.2 gradients - pearson levelle homework questions · c line 3: gradient = = −3 d line 4:...
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9.2 Gradients 1 a Complete this table for the equation y = 2x − 3.
x −2 −1 0 1 2
y −7
b Plot your points from your table and draw a straight line through your points.
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a Which of the line segments in the diagram have:
i a positive gradient ......................
ii a negative gradient? ......................
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b Work out the gradient of each of the line segments in the diagram.
line 1 .....................................................................................................................................
line 2 .....................................................................................................................................
line 3 .....................................................................................................................................
line 4 .....................................................................................................................................
line 5 .....................................................................................................................................
line 6 .....................................................................................................................................
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a Complete the table of values for each graph. Use the completed tables to plot each graph. Label each graph with its equation.
i y = x + 3
x −2 −1 0 1 2 3
y 1 2
ii y = 3x − 2
x −2 −1 0 1 2 3
y −5 −2
iii y = −2x + 5
x −2 −1 0 1 2 3
y 9
b Calculate the gradient of each graph.
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c From your tables, look at the sequence for the y values. How does this connect to the gradient?
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d From the equations, look at the coefficient of x. How does this connect to the gradient?
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9.2 Gradients 1 a i Plot a graph by using the values
from the table.
x −2 −1 0 1 2
y −7 −4 −1 2 5
ii Work out the gradient of your graph from part i.
..................................................
b i Swap the x- and y-values and plot a new graph on the same axes.
ii Work out the gradient of the new line.
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c i Plot a graph by using the values from the table.
x −2 −1 0 1 2
y −5 −3 −1 1 3
ii Work out the gradient of your graph from part i.
..................................................
d i Swap the x- and y-values and plot a new graph on the same axes.
ii Work out the gradient of the new line.
..................................................
e Look at your gradients. Is there a connection between the original gradients and the gradients of the new lines? ......................
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2 a Use the graph to complete the table below.
x −2 −1 0 1 2
y-values (A)
y-values (B)
b What is the gradient of each line?
line A ......................
line B ......................
c What is the mathematical relationship between lines A and B?
..............................................................................................................................................
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9.2 Gradients 1
Complete each statement. Use the diagram to help.
The first one has been done for you.
a Line 1 goes 3 units up for every 1 unit to the right.
b Line 2 goes ……. unit(s) up for every ……. unit(s) to the right.
c Line 3 goes ……. unit(s) up for every ……. unit(s) to the right.
d Line 4 goes 2 units down for every ……. unit(s) to the right.
e Line 5 goes ……. unit(s) down for every ……. unit(s) to the right.
f Line 6 goes ……. unit(s) down for every ……. unit(s) to the right.
2 Using your answers to Q1, complete to work out the gradient of each line.
a Line 1: gradient = = 3 b Line 2: gradient = = …….
c Line 3: gradient = = ……. d Line 4: gradient = = …….
e Line 5: gradient = = ……. f Line 6: gradient = = …….
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3
Complete each statement. Use the diagram to help.
a Line 1 goes ……. unit(s) up for every ……. unit(s) to the right.
b Line 2 goes ……. unit(s) up for every ……. unit(s) to the right.
c Line 3 goes ……. unit(s) down for every ……. unit(s) to the right.
d Line 4 goes ……. unit(s) down for every ……. unit(s) to the right.
4 Using your answers to Q3, complete to work out the gradient of each line.
a Line 1: gradient = = …….
b Line 2: gradient = = …….
c Line 3: gradient = = …….
d Line 4: gradient = = …….
5 For Q3 a student says, ‘Line 4 has a negative gradient.’ Is the student correct? Explain how you know.
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9.2 Gradients Core 1 a b
x −2 −1 0 1 2
y −7 −5 −3 −1 1
2 a i Lines 1, 3 and 4 ii Lines 2, 5 and 6
b Line 1 = 2, line 2 = −3, line 3 = 1,
line 4 = , line 5 = −1 and line 6 =
3 a i x −2 −1 0 1 2
y 1 2 3 4 5
ii
x −2 −1 0 1 2
y −8 −5 −2 1 4
iii
x −2 −1 0 1 2
y 9 7 5 3 1
b Gradients are 1, 3 and −2
c For i), the y-values increase by 1 and the gradient is 1. For ii), the y-values increase by 3 and the gradient is 3. For iii), the y-values decrease by 2 and the gradient is −2.
d The gradient matches the coefficient of x.
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Depth 1 a i See graph
ii Gradient = 3
b i See graph
ii Gradient =
c i See graph
ii Gradient = 2
d i See graph
ii Gradient =
e The new gradients are the reciprocals of the original gradients.
2 a
x −2 −1 0 1 2
y-values (A) 3 1 −1 −3 −6
y-values (B) −2 −1.5 −1 0.5 0
b The gradient of line A is −2.
The gradient of line B is
c The lines are perpendicular to each other.
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Support 1 b Line 2 goes 1 unit up for every 2 units to the right.
c Line 3 goes 4 units up for every 1 unit to the right.
d Line 4 goes 2 units down for every 1 unit to the right.
e Line 5 goes 1 unit down for every 3 units to the right.
f Line 6 goes 4 units down for every 1 unit to the right.
2 a Line 1: gradient = = 3 b Line 2: gradient = =
c Line 3: gradient = = 4 d Line 4: gradient = = −2
e Line 5: gradient = = f Line 6: gradient = = −4
3 a Line 1 goes 2 units up for every 1 unit to the right.
b Line 2 goes 1 unit up for every 3 units to the right.
c Line 3 goes 3 units down for every 1 unit to the right.
d Line 4 goes 1 unit down for every 2 units to the right.
4 a Line 1: gradient = = 2 b Line 2: gradient = =
c Line 3: gradient = = −3 d Line 4: gradient = =
5 Yes, the student is correct. The line slopes downwards so has a negative gradient. Alternatively, from Q4 we can see the value is a negative number.
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