Section 5.1: Integer Exponents
Recall the meaning of the exponential form of a number.
23means “three factors of 2”. This can
be written in expanded form as 2•2•2 , and its value is 8.
In the exponential form, an, a is the base and n
is the exponent.
A. The Product Rule for Exponents states that “if you multiply two numbers
(in exponential
form) that have the same base, you get a number (in exponential form) with the
same base
and the exponent is found by adding the exponents of the two original numbers
(in
exponential form)”. In symbols, we have:
Ex. Multiply using the product rule:
Ex. Multiply using the product rule:
Ex. Simplify:
B. The Quotient Rule for Exponents states that “if you
divide two nonzero numbers (in
exponential form) with the same base, you get a number with the same base and
the
exponent is found by subtracting the exponent of the denominator from the
exponent of the
numerator”. In symbols, we have:
Ex. Simplify and write you answer using positive
exponents:
Ex. Simplify and write you answer using positive exponents :
C. The Zero Exponent Rule states that “any nonzero
number raised to the zero power is equal
to 1”. In symbols, we have:
Ex. Simplify:
Since the base of this expression is −5 (which is not equal to zero), the zero
exponent rule applies.
Ex. Simplify:
The base of this expression is 3 (which is not zero),
so the zero exponent rule
applies, but only to the base of 3!
Ex. Simplify:
Here, the base is 2x and we know that x≠0, so
2x≠0 ,and ,so the zero
exponent rule applies to the base 2x.
Ex. Simplify:
Here, the base is x and we know that x≠0, so the zero
exponent rule applies
to the base x.
D. The Negative Exponent Rule states that “any nonzero base raised to a
negative power is
equal to the 1 divided by the same base raised to the opposite of the negative
power”. In
symbols, we have:
Ex. Simplify and write you answer using positive
exponents:
Ex. Simplify and write you answer using positive
exponents:
Ex. Simplify and write you answer using positive
exponents:
Ex. Simplify and write you answer using positive
exponents
Ex. Simplify and write you answer using positive
exponents:
D.
E. There are three Power Rules for exponents.
1. The Basic Power Rule for Exponents states that “any exponential expression
that is
raised to a power is equal to an exponential expression with the same base and
exponent that is found by multiplying the exponents in the problem”. In symbols,
we have:
Ex. Simplify:
2. The Power of a Product Rule for Exponents states
that “if you have a power of the
product of two (or more) numbers, raise each factor of the product to the new
power”. In symbols, we have:
Ex. Simplify:
3. The Power of a Quotient Rule for Exponents states
that “if you have a quotient of
of two nonzero numbers, raise the numerator and denominator each to the new
power”. In symbols, we have:
Ex. Simplify:
E.
F. There are some Special Rules for exponents that are
helpful in very specific situations. You
may use these if you like , but you are not required to know them. All problems
can be
worked using the previously stated rules.
G. Assignment
Pages 294 – 297: 7 – 15 odd, 19 – 29 odd, 33 – 47 odd, 51 – 57 odd, 63 – 125 odd