SOFTWARE
PREVIEWS
From here you can access many
interactive routines that make up our mathematics and physics
courses.
Please feel free to experiment and don't hesitate to contact us
in case you have any questions.
Graphs of linear functions of the form y = mx + b [click]
Properties of powers [click]
Did you know? [click]
The principle of energy conversion [click]
The meaning of an increment [click]
The hydraulic press [click]
PROPERTIES OF POWERS
Now it's time for us to learn more
about powers. As many algebraic operations, powers
have their own properties,
which are easily understood once we remember what
are the exponent and the base of a power. There
are five major properties of powers, which serve
as
a
pathway
to factoring, as well as to many other areas
of mathematics, including geometry.
During
multiplication of powers with the same base, the
exponents are added while the base remains unchanged.
Let us review some examples. Indeed,
in accordance with the definition of power with natural
exponent:
Important: pay attention to the fact that base does
not change. See examples below:
During
division of powers with the same bases, the base
remains the same while the exponents are subtracted.
Or, since division is a particular
case of a fraction and vice-versa:
Which is still the same operation
of division, after all. Yet again, let us review some
examples:
Also look at these examples:
During
powering of the power, the base remains the same,
while exponents are multiplied by each-other.
In general form this property will look like this:
This property will be different.
Before it we were dealing only with the same bases,
this time
it is going to change: we
are going to deal with the product of different bases.
It's enough to remember that many numbers could be represented
as products: 12 = 3x4 or 2x6, or 25 = 5x5 and thus:
During
powering of the product, each multiplier of this
product should be raised to the same power.
There was a reason for us mentioning
representing numbers as products: often you will
encounter a situation when you have to represent a
number as a product. See for yourself: 123 is
just that 12 cubed, but there will be situations when
you will have to represent this number as a product.
In this case Property 4 will come
in handy. 12, of course, could be represented as a
product in two
ways: 4.3
and 6.2 so now we can power both of these
products:
This property is so simple that
requires no additional explanations, and, at a close
inspection, bears an uncanny
resemblance to the distributive property of multiplication.
In the case of the powers we
"distribute" not the factor but the exponent:
or
other way around (of course, only is the different bases
will have the same exponent:
)
The
power of a fraction can be represented as a
fraction of the powers with the
numerator and the denominator of this fraction as
the bases:
Here, we "distribute"
our exponent to both the numerator and the denominator
and this
is the whole trick.
See examples below:
So, now we know 5 fundamental properties
of powers. At first this looks simple but later on
more complex exercises will teach you how to apply
these
properties
separately, consecutively, and later, in a complex
and sophisticated sequences.
Now
let's try a practical assignment..