A Level Maths Notes: FP1 – Multiplying and Dividing Complex Numbers
Complex numbers can be expressed in two forms:
Coordinate form:
and
Polar form
Multiplying Complex Numbers
The rules for multiplying and dividing complex numbers follow the normal rules of arithmetic.
If
and
then
we expand brackets
If
and
are
in polar form then we multiply the magnitudes R-1 and R_2 and add the
arguments, which are also the exponents.
Dividing Complex Numbers
Ifandthen
we make the denominator real by multiplying by the complex conjugate
of the denominator
Ifandare
in polar form then we divide the magnitudes
and
and
add the arguments, which are also the exponents.
Example: Find the product and quotient of
and
Example: Find the product and quotient of
and
