3 Sequences, functions and graphs
Start with Concept to understand a topic, then use Question Bank to check what you know.
Your progress
Sign in to see your mastery and mistakes.
3.1 Sequences
generate terms of a sequence using term-to-term and position-to-term definitions of the sequence Including odd, even, squares, multiples and powers
find subsequent terms of an integer sequence and the rule for generating it 5, 9, 13, 17, … (add 4) 1, 2, 4, 8, … ( multiply by 2)
use linear expressions to describe the nth term of arithmetic sequences 1, 3, 5, 7, 9, … nth term is 2n – 1 nth term is 4n + 3, write down the first 3 terms of the sequence
understand and use common difference (d) and first term (a) in an arithmetic sequence e.g. given 2nd term is 7 and 5th term is 19, find a and d
know and use the nth-term formula a + (n − 1)d for an arithmetic sequence
find the sum of the first n terms of an arithmetic series (Sn) e.g. given 4 + 7 + 10 + 13 + … find sum of first 50 terms
3.2 Function notation
Understand a function as a mapping between elements of two sets.
use function notation in the forms f(x) = … and f : x ↦ …
understand domain and range, including values excluded from a domain, such as x = 2 for f(x) = 1/(x − 2)
understand and find the composite function fg and the inverse function f⁻¹; fg means apply g first, then f
3.3 Graphs
3.3.AInterpreting linear and non-linear graphs
interpret information presented in a range of linear and non-linear graphs To include speed/time and distance/time graphs
3.3.BCartesian coordinate conventions
understand and use conventions for rectangular Cartesian coordinates
3.3.CPoints (x, y) in any of the four quadrants or locate
plot points (x, y) in any of the four quadrants or locate points with given coordinates
3.3.DThe coordinates of points identified by geometrical
determine the coordinates of points identified by geometrical information
3.3.EMidpoint coordinates
Determine a line segment’s midpoint from the coordinates of its endpoints.
3.3.FStraight-line conversion graphs
Draw and interpret straight-line conversion graphs, including currency-conversion graphs.
3.3.GGradient of a straight line
find the gradient of a straight line gradient = (increase in y) ÷ (increase in x)
3.3.HStraight-line graphs in the form y = mx + c
recognise that equations of the form y = mx + c are straight line graphs with gradient m and intercept on the y-axis at the point (0, c) Write down the gradient and coordinates of the y intercept of y = 3x + 5; Write down the equation of the straight line with gradient 6 that passes through the point (0, 2)
3.3.ILinear and quadratic function graphs
Recognise, generate points and plot linear and quadratic function graphs, including tables and equations of the form ax + by = c.
3.3.HAPolynomial, reciprocal and trigonometric graphs
recognise, plot and draw graphs of y = Ax³ + Bx² + Cx + D; y = Ax³ + Bx² + Cx + D + E/x + F/x² where at least three constants are zero; and y = sin x, y = cos x and y = tan x for angles of any size in degrees; x and y may be replaced by other variables
3.3.HBTransformations of graphs
apply to the graph of y = f(x) the transformations y = f(x) + a, y = f(ax), y = f(x + a), y = af(x) for linear, quadratic, sine and cosine functions
3.3.HCAnalysing transformations of functions
interpret and analyse transformations of functions and write the functions algebraically
3.3.HDThe gradients of non-linear graphs By drawing a tangent
find the gradients of non-linear graphs By drawing a tangent
3.3.HEIntersections of linear and non-linear graphs
find intersections of a linear graph y₁ and a non-linear graph y₂, and recognise that their x-coordinates solve y₂ − y₁ = 0
3.3.HFGradient from two points
Calculate a straight line’s gradient from the coordinates of two points.
3.3.HGParallel and perpendicular line equations
Find equations of straight lines parallel or perpendicular to a given line.
3.4 Calculus
Understand the concept of a variable rate of change.
differentiate integer powers of x
determine gradients, rates of change, stationary points, turning points (maxima and minima) by differentiation and relate these to graphs Find the coordinates of the maximum and minimum points
distinguish between maxima and minima by considering the general shape of the graph only
apply calculus to linear kinematics and other simple practical problems