University Prep Math
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A function The relationship between two variables. y = 2x is a relationship between two variables (x and y). In this case, the function says “y is always twice University Prep Math Steve Greer [email protected] hrsbstaff.ednet.ns.ca/sgreer Phrase or Term Definition Example A variable The letter which stands for a number that can change. ‘x’ in 2x-6 is a variable. Its value could be 4, or -6, or any other number. A function The relationship between two variables. y = 2x is a relationship between two variables (x and y). In this case, the function says “y is always twice
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University Prep Math. Steve Greer [email protected] hrsbstaff.ednet.ns.ca/ sgreer. Order of Operations: When to do what. B E D M A S. I V I S I ON. DD I T I ON. R A C K E T S. X P ON E N T S. U B T R A C T I ON. U L T I P L A C T I ON. - PowerPoint PPT Presentation
Transcript of University Prep Math
Phrase or Term Definition Example
A variable The letter which stands for a number that can change.
‘x’ in 2x-6 is a variable. Its value could be 4, or -6, or any other number.
A function The relationship between two variables.
y = 2x is a relationship between two variables (x and y). In this case, the function says “y is always twice as much as x”.
University Prep MathSteve Greer
[email protected]/sgreer
Phrase or Term Definition Example
A variable The letter which stands for a number that can change.
‘x’ in 2x-6 is a variable. Its value could be 4, or -6, or any other number.
Phrase or Term Definition ExamplePhrase or Term Definition Example
A variable The letter which stands for a number that can change.
‘x’ in 2x-6 is a variable. Its value could be 4, or -6, or any other number.
A function The relationship between two variables.
y = 2x is a relationship between two variables (x and y). In this case, the function says “y is always twice as much as x”.
Evaluating an expression Finding out what the value of the expression is when you know the value of the variable.
Evaluate: 4x-1 when x = 3.We plug in a 3 wherever we see an ‘x’ and follow the order of operations.
Order of Operations: When to do what
B E D M A SRACKETS
XPONENTS
IVISION
ULTIPLACTION
DDITION
UBTRACTION
“Evaluating an Expression” examples
Evaluate the following expressions given the value of the variable stated.
1. 7x-3 if x = 7 2. 10(x-2) if x = 4
3. 5r -7t -6 if r = 2 and t = 1 4. 3t2 +5t -9 if t = 2
5. 3x(x-2) + x/2 if x = 4 6. if j = 3
jj
2
5
Answers: 1. 46 2. 20 3. -3 4. 13 5. 26 6. 1
Phrase or Term Definition Example
Solving an equation or finding the roots.
Finding out what the value of the variable is when you know what the expression equals. This is the opposite as evaluating the expression. Root – the value of the variable that makes the equation true.
Solve for ‘x’.
3x-4 = 8
We will “undo” BEDMAS
Find the root of each equation.
1) 5(x-4) = 10 2) 8w – 2 = -42
3) ½ (g+1) = 6 4) 3x + 6 = 9x – 4
5) 6) 913
4 r19247 mm
Answers: 1) 6 2) -5 3) 11
4) 10/6 = 1.67
5) 26 6) -3
Where do these functions come from?
We have worked with a few expressions and a few equations but what do they mean? Let’s look out how our every day lives use functions all the time!
Cell Phone Bill – A function
What are two variables involved in cell phone use?We can find a relationship between the cost of the bill and the time of usage. Which variable depends on the other?
Let’s say that it costs 20 cents per minute and that you are always charged a monthly fee of $7.00. Questions: 1) What is the function and its graph?
2) If you talked for 45 minutes, what will your bill be? 3) If your bill is $37.40, how many minutes were you
on the phone?
