using a negative exponent
DESCRIPTION
Strobes. The picture of the golf ball was taken using a strobe light. Each flash of the strobe light lasted about 1 microsecond. How can you write this time in seconds as a power of ten?. 1. 1 microsecond is equal to. second. 1,000,000. EXAMPLE 1. Using a Negative Exponent. SOLUTION. - PowerPoint PPT PresentationTRANSCRIPT
Using a Negative ExponentEXAMPLE 1
Strobes
The picture of the golf ball was taken using a strobe light. Each flash of the strobe light lasted about 1 microsecond. How can you write this time in seconds as a power of ten?
SOLUTION
The flash lasts 1 microsecond. Because the prefix micro means one millionth of a unit, you know that
1 microsecond is equal to 11,000,000 second.
Using a Negative ExponentEXAMPLE 1
11,000,000 = 106
1 Write 1,000,000 as 106.
= 10– 6 Definition of negative exponent
One flash of the strobe light lasts about 10 – 6 second.
ANSWER
Evaluating a Numerical ExpressionEXAMPLE 2
Evaluate the expression.
Product of powers property
= 5– 3 Simplify.
= 153
Definition of negative exponent
= 1125
Evaluate the power.
= 5 2 + (– 5)52 5– 5
Simplifying Variable ExpressionsEXAMPLE 3
Zero exponent applies only to n.
Definition of zero exponent
Multiply.
Simplify. Write the expression using only positive exponents.
a. – 2n0
– 2 • 1=
= – 2
= – 2 • n0
= 8 •x-3-1
8x-3
xb.
Quotient of powers property
Subtract exponents.
= 8 • x-3
x1 Exponent applies only to x
= 8 •x-4
8 x4 Definition of negative exponent
GUIDED PRACTICE for Examples 3 and 4
1. What If ? In Example 1, suppose the flash of a light lasted about one thousandth of a second. Write this time in seconds as a power of 10.
GUIDED PRACTICE for Examples 3 and 4
ANSWER
One flash of the strobe light lasts about 103 second.
GUIDED PRACTICE for Examples 3 and 4
2. 7–2 = 1 49
3. (–2)–5 = 1 32
–
GUIDED PRACTICE for Examples 3 and 4
= 1 364. 6 6–3
GUIDED PRACTICE for Examples 3 and 4
= 15. 10–5 10 5
GUIDED PRACTICE for Examples 3 and 4
6. –6m –1 = –6 m
Simplify. Write the expression using only positive exponents.
GUIDED PRACTICE for Examples 3 and 4
= 17. b2 b–2
8. 5x4
x –7 = 5x11
GUIDED PRACTICE for Examples 3 and 4
= 10 a7
9. 10a– 3
a4