A-Level Maths OCR B (MEI) H640

3: Functions

#3.1

Polynomials

Be able to add, subtract, multiply and divide polynomials.

Expanding brackets and collecting like terms.

[Excludes: Division by non-linear expressions.]

#3.2

Factor theorem

Understand the factor theorem and be able to use it to factorise a polynomial or to determine its zeros.

f(a)=0    (xa)f(a)=0 \iff (x - a) is a factor of f(x)f(x).

Including when solving a polynomial equation.

[Excludes: Equations of degree > 4.]

#3.3

Functions

Understand the definition of a function, and be able to use the associated language.

A function is a mapping from the domain to the range such that for each xx in the domain, there is a unique yy in the range with f(x)=yf(x) = y. The range is the set of all possible values of f(x)f(x).

Notation:

  • Many-to-one, one-to-one, domain, range, f:xyf:x→y
#3.4

Composite functions

Understand and use composite functions.

Includes finding the correct domain of gfgf given the domains of ff and gg.

Notation:

  • gf(x)gf(x)
#3.5

Inverse functions

Understand and be able to use inverse functions and their graphs. Know the conditions necessary for the inverse of a function to exist and how to find it.

Includes using reflection in the line y=xy = x and finding domain and range of an inverse function.

e.g. lnx (x>0)\ln{x}~(x > 0) is the inverse of exe^x.

Notation:

  • f1(x)f^{-1}(x)
#3.6

Modulus function

Understand and be able to use the modulus function.

Graphs of the modulus of linear functions involving a single modulus sign.

#3.7

Solve inequalities involving the modulus

Be able to solve simple inequalities containing a modulus sign.

Including the use of inequalities of the form xab|x - a| ≤ b to express upper and lower bounds, a±ba \pm b, for the value of xx.

[Excludes: Inequalities involving more than one modulus sign or modulus of non-linear functions.]

#3.8

Use functions in modelling

Be able to use functions in modelling.

Including consideration of limitations and refinements of the models.

2
Algebra
4
Graphs