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Maths · Functions, Sequences and Rates of Change

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Maths · OCR Paper 1

Functions, Sequences and Rates of Change

Functions and Function Notation (Higher tier)

Using f(x) notation, composite functions such as fg(x), and inverse functions.

  • Function A rule that gives one output for each input.
  • Function notation Writing a function as f(x).
  • Input The value put into a function.
A function machine that multiplies the input x by 3 and then subtracts 5, giving the output 3x minus 5.

Geometric and Special Sequences

Recognising geometric and Fibonacci-type sequences, and finding the common ratio from two terms.

  • Geometric sequence A sequence with a common ratio between terms.
  • Common ratio The number each term is multiplied by.
  • Term-to-term rule A rule that gives each term from the one before it.
The sequence 2, 6, 18, 54, 162 with an arrow labelled times 3 between each pair of terms.

Iteration (Higher tier)

Using iterative formulae, rearranging equations, and finding roots by a change of sign and trial and improvement.

  • Iteration A process that is repeated, using each output as the next input.
  • Iterative formula A formula that gives the next value from the current one.
  • Limit The value that the terms of an iteration approach.
An iteration machine that takes x sub n, calculates 3 minus 2 over x sub n, and feeds the result back in as the next input.

Rates of Change and Areas Under Graphs (Higher tier)

Finding gradients of curves with tangents, average rates of change, and estimating areas under graphs with trapezia.

  • Tangent A straight line that touches a curve at one point.
  • Chord A straight line joining two points on a curve.
  • Gradient A measure of the steepness of a line.
The curve y equals x squared with a tangent at the point (2, 4), and a triangle showing a rise of 8 and a run of 2.

Transformations of Graphs (Higher tier)

Sketching and describing translations and reflections of graphs, including trigonometric graphs.

  • Transformation A change to the position or shape of a graph.
  • Translation A movement of a graph without turning or flipping it.
  • Reflection A flip of a graph in a line, such as an axis.
Four transformations of a U-shaped curve with its turning point at (2, minus 1), showing a translation up, a translation left, a reflection in the x-axis and a reflection in the y-axis.