Home
Subjects
Create
Search
Log in
Sign up
Upgrade to remove ads
Only $2.99/month
Pre-Algebra Quiz 6-4 Day 2 - 6-5 2021
STUDY
Flashcards
Learn
Write
Spell
Test
PLAY
Match
Gravity
Just Do It ;P
Terms in this set (26)
Fun Fact
You can use what you know about functions and apply them to real life problems. The charts and graphs you generate can help you to predict information not found in the original data.
Words to Know: Function
a relationship between two variables
ex: 3x + 4y = 1
ex: y = 2x + 1
ex: y = x
Words to Know: Input
X the number that you substituted for x to find y
Words to Know: Output
Y the number that you calculate by substituting x
Words to Know: Function Form
y = mx + b (slope-intercept form - you can say either)
y is ISOLATED
Words to Know: Independent Variable
What the scientist changes or what changes on its own
( x - axis )
ex: Time, input
Words to Know: Dependent Variable
What is being studied/measured
( y - axis )
ex: calculated, output
1. An attorney charges a fixed fee of $250 for an initial meeting and $150 per hour for all hours after that. Make a table of the total charge for 0,1,2,3 and 4 hours worked. Sketch a graph, write the linear equation, and answer the question
Independent variable & units #hours (input)
0 1 2 3 4
Dependent variable & units $total charge (output)
250 400 550 700 850
(0,250), (1,400), (2,550), (3,700), (4,850)
1 cont. What function (equation of our line) represents the graph?
m = rise/run
m = 150/1
y-int: (0,250)
y = mx + b
y = 150x + 250
1 cont cont. What is the charge for 25 hours of the attorney's work?
y = the charge, 25 = x
y = 150x + 250
y = 150(25) + 250
y = 3750 + 250
y = $4000
Don't forget units!!
2. A water tank contains 55 gallons of water when Darius begins to fill it. Water flows into the tank at a rate of 9 gallons per minute. Complete the table, write the equation, and answer the question.
x Independent variable & units #min (input)
0 1 2 3 4 5
y Dependent variable & units #gal (output)
55, 64, 73, 82, 91, 100
2 cont. (no graph) What function represents this table?
#gallons = water in tank + water added each min
y = 55 + 9x
2 cont cont. Find the volume if water in the tank after Darius has filled it for 20 minutes.
y = 55 + 9x
y = 55 + 9(20)
y = 55 + 190
y = 235 gal
3. An airport parking lot charges a basic fee of $2 plus $1 per half hour. Write an equation for the total charge in terms of hours parked. Watch your units!
Let y = the total fee, Let x = #of hours parked
total = start fee + cost per hour
y = 2 + 2x
3 cont. Predict the cost of parking for 7 hours (no graph)
y = 2 +2(7)
y = 2 + 14
y = 16 dollars
4. The table shows the average speeds of the winners of the Daytona 500. Graph the data. Can you use the graph to predict future winning speeds? Explain why or why not.
Year, x 2004,2005,2006,2007,2008, 2009, 2010, 2011, 2012
Speed,(mi/h) y 156, 135, 143, 149, 153, 133, 137, 130, 140
After we plotted the ordered pairs,
we saw that the points were to erratic to form a linear equation.
If you can't see the linear relationship, you can't find the future
Important to Know: What is formula for the Slope-Intercept Form?
y = mx + b
y = 1/3x + 4
Skill 1: Using the Slope-Intercept Formula to write the equation of the line
Wrote the equation of the line given the slope and y-intercept below. Begin by writing the slop-intercept formula every time.
m = 1/2 y-int: (0,-6)
y = mx + b
y = 1/2x -6
Skill 1: -5/6 ~ y-int (0,0)
y = mx + b
y = -5/6 + 0
y = -5/6x
double check you added everything!
Skill 1: m = 0 ~ y-int: (0,9)
y = mx + b
y = 0x + 9
y = 9
0x means you have to cross it out!!
y = # = HOY
Skill 1: m = undefined ~ x-int: (2,0)
Vertical line - VUX - x = #
x = 2
just plug in the x-int
Skill 2: Find the equation of the line by looking at a graph - use the graph to identify the slope and the y-int of each line. Then, use the slop-intercept formula to write the equation of the line. Make certain to include both formulas for every problem
m = ? b = ?
m = rise/run
m = -8/10
m = -4/5
y-int: (0,-2)
b = -2
y = mx + b
y -4/5x + -2
Skill 2 cont. w/ a horizontal line m = ? b = ?
m = 0
y-int: (0,-7)
b = -7
y = mx + b
y = 0x + -7
y = -7
HOY
Skill 2 cont. w/ vertical line m = ? b = ?
m = undefined b = NO x-int: (2,0)
VUX x = #
x = 2
Skill 3: Find the equation of the line without a graph
1) Write the equation of the line between the points (0,3) and (4, -5) Include all formulas
1) m = ?
m = y2 - y1/x2 - x1
m = (-5) - (3)/(4) - (0)
m = -8/4
m = -2
2) b = ? (4, -5)
y = mx = b
(-5) = (-2)(4) + b
-5 = -8 + b
3 = b
3) Plug it in
y = mx + b
y = -2x + 3
This set is often in folders with...
Pre-Algebra Quiz 7-1 to 7-2 2021
28 terms
Pre-Algebra Quiz 7-3 Day 1 to 7-5 2021
24 terms
Math Terms
50 terms
Pre-Algebra Quiz 7-5 ~ 7-6
16 terms
Other sets by this creator
French 1A: Le Verbe Faire
53 terms
To go, at the, to the, in the, for the, from the,…
13 terms
Pre-Algebra Quiz 6-3 Day 1 ~ 6-4 Day 1 2021
43 terms
Pre-Algebra Important To Know Test 5 Unit 5 2021
53 terms
Other Quizlet sets
chemistry ch 14 and 15
44 terms
MIDTERM STUDY Guide-Part 1
18 terms
Constitutional Convention
18 terms
Chapter 7: English Policies
10 terms