10/13 Bell Ringer
Step 1: Grab materials from front of the room.
Step 2: Solve for x in the following 3 problems:
1. 3x = 12
2. x – 5 = 9
3. 3x – 5 = 13
4. BONUS: 2x + 3x – 5 = 0
HOMEWORK: INVERSE OF LINEAR FUNCTIONS HOMEWORK,
Potential QUIZ FRIDAY!!!
10/13 News and Notes
• Quizzes handed back? Missing quizzes:
Abriona, Diana, Santos, Raven, Monica,
Alexis, Michael, Crystal, Shamika
• Next quiz on Friday.
• Homework is incredibly important these next
2 days!
10/13 Agenda
• I CAN solve for inverse of linear function.
1. Bell Ringer
2. New Material – 2 examples
3. Guided Practice – Graph Paper!
4. Independent Practice (Homework).
Example 1
• Find the inverse function of f(x) = 2x – 6.
• Step 1: f(x) is just another way of saying y.
Substitute y back in.
y  2x  6
x  2y  6
• Step 2: Switch x & y
x  2y  6
• Step 3: Isolate or solve for y.  6  6
– 3a. Add or Subtract b
– 3b. Divide by coefficient
• Step 4: Switch f-1(x) for y.
x  6  2y
x 6 2y
 
2 2 2
1
x3 y
2
1
1
f ( x)  x  3
2
Example 2
•
•
•
•
•
•
f(x) = 3x + 7. Find inverse function.
1: y = 3x + 7
2: x = 3y + 7
3: -7
-7
x – 7 = 3y
3 3 3
1
7
x  y
3
3
• 4:
1
7
f ( x)  x 
3
3
1
What if you have to graph it?
Take original equation and set up table, then do
Friday’s work.
Example: f(x) = 3x + 7
f(x) = 3(-2) + 7
f(x) = -6 + 7
f(x) = 1 = y
X
Y
-2
1
-1
0
4
7
1
10
2
13
You could then solve for the equation of the
inverse graph.
Now you have a choice.
• You are either telling yourself one of two things
right now:
– 1. I need more practice solving for the inverse
– OR
– 2. I’ve got this, let me do something on my own
• If you are more like 1, go to the whiteboard side
of the room and get out notebook paper.
• If you are more like 2, go to window side of room
and read the next slide.
• 30 seconds, GO!
Project – Neatness Matters!
• You need a piece of graph paper (located on front desk).
• Take f(x) = 2x – 6 and follow the steps below:
• Step 1: Create a table with x values (-2, -1, 0, 1, 2) and fill in
y values.
• Step 2: Graph f(x)
• Step 3: Graph f-1(x) by switching x and y in table
• Step 4: Solve to find the equation of f-1(x) showing all work
on your paper.
• Step 5: Identify slope of inverse, domain and range of
inverse.
• Step 5: If you finish, see if you can repeat for f(x) = ½ x + ¼