Transcript Example 5 cont`d

Warmup 8/29/12
Example 5: The formula C = 5(F -32)
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Can be used to convert temperatures in degrees
Fahrenheit to degrees Celsius.
a)
Room temperature commonly ranges from
64 F to 73 F. Determine the room
temperature range in degrees Celsius.
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Example 5 cont’d
B) The normal average human body
temperature is 98.6 F. A temperature above
this indicates a fever. If your temperature is 42
C, do you have a fever? Explain your answer.
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Example 6: The radius of the earth’s orbit is
93,000,000 miles.
A)Find the circumference of the Earth’s orbit
assuming that the orbit is a circle. The formula
for the circumference of a circle is C = 2iir.
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B) Earth travels at a speed of 66,698 miles per hour
around the sun. Use the formula T = c
v
where T is the time in hours, C is the circumference,
and V is the velocity, to find the number of hours it
takes the Earth to revolve around the sun.
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C) Did you prove that it takes one year for the
earth to go around the sun? Explain your
answer.
1.2 Properties of Real Numbers
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Real numbers (R) – all numbers that you use
in everyday life.
2 categories:
1. Rational (Q)– expressed as a ratio m / n, where
m and n are integers and n is not zero.
*Decimals – STOP or repeat
ex. 1/6, 1.9, 2.575757…., -3, 0
2. Irrational (I) – Decimal does not STOP or
repeat
Ex. √5, ∏, .010010001. . . . .
Real Numbers
Rational
Integers
Whole
Natural
Irrational
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Integers (Z)– all numbers you can write on the
number line. ex…...-2, -1, 0, 1, 2.....
Whole numbers (W)– ex. 0, 1, 2, 3,……….
Natural numbers (N)– ex. 1, 2, 3, . ………
Example 1:
Name the sets of numbers to which each number
belongs.
A. √16 = 4
*R, Q, Z, W, N
B. -185
*R, Q, Z
C. √20 = 4.47213…
*R, I
D. -7/8 = .875
*R, Q
E. 0.45
*R, Q
Real Numbers Properties
Property
Addition
Multiplication
Commutative
a+b=b+a
axb=bxa
Associative
(a + b) + c = a + (b + c)
(a x b) x c = a x (b x c)
Identity
a+0=a=0+a
ax1=a=1xa
Inverse
a + (-a) = 0 = (-a) + a
If a ≠0, then a x 1/a = 1 = 1/a x a
Distributive
a(b + c) = ab + ac and (b + c)a = ba + ca
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Example 2: Name the property illustrated.
a. (5 + 7) + 8 = 8 + (5 + 7)
b. 3(4x) = (3x4)x
Example 3: Identify the additive inverse and
multiplicative inverse.
a. -1¾ = -7/4
*Additive = -1¾ + 1¾ = 0
*Multiplicative = (-7/4) x (-4/7) = 1
Warmup 8/30/12
Name the property.
a. (5 + 7) + 8 = 8 + (5 + 7)
b. 3(4x) = (3x4)x
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Example 3:
b. 1.25
*Additive = 1.25 + (-1.25) = 0
*Multiplicative = 1.25 x 1/ 1.25 = 1
Word Problem
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Julie is making curtains out of the same fabric for 5
windows. The 2 larger windows are the same size and the
3 smaller windows are the same size. One larger window
requires 3¾yds of fabric and one smaller window needs
2⅓ yds of fabric. How many total yards of fabric will
Julie need?