Algebra 1
• Define a rational exponent.
• Define square roots and radical form.
• Define and apply the n th root.
• Evaluate n th root expressions.
Rational exponents are exponents that contain fractions. We can also rewrite them using radicals ! Try finding the patterns below…use your calculator to evaluate the following! ๏
What do you notice???
๐
1
2 = ๐
Practice converting back and forth between exponential form and radical form. Use the formula above to help you!
Square Root Definition
What is another way we can think about this?
Recall Exponents:
4 2 = 4 ๏ 4
What if we had something that looks like this…
2
1
16 ๐๐ 16 2
Remember, this is saying that I want to multiply the base number out 2 times or write out the expression using 2 pieces!
Now we know what our answer is from the last slide. However think about what we said to the left. This is asking us to split 16 up into 2 equal pieces…but we only want 1 out of the 2 . Hence the term ROOT when you write it as a radical! ๏
How can I break 16 down into 2 equal
4 4
#1:
What is
81
1
2
?
# 2:
Find 100 100
1 (or ___)
81 = ___ โ ___
100 = ___ โ ___
Thus,
81
1
2
= ___
Thus,
100 = ___
We can also use this same logic for some other problems too!
What if I have something like…
81
1
4
This is now saying that I know 81 can be written as 4 equal pieces and I only want 1 of those 4 pieces.
How can I break 81 down into 4 equal pieces?
___ โ ___ โ ___ โ ___
What would my answer by if I want only
1 out of those 4? ____
๐ ๐กโ
#1) What is 27
1
3
?
#2) Find 5
32 (or ___)
27 = __ โ __ โ __
32 = __ โ __ โ __ โ __ โ __
Thus, 27
1
3
= __
Thus, 5
32 = __
What have we been doing every time to rewrite the expression from radical form to exponential form?
๐ ๐กโ
1 ๐ ๐ = ๐ ๐
#3) What is 64
1
3
?
#4) Find 3
125
Use the same logic for advanced ๐ ๐กโ roots too! ๏
What if I have something like…
16
3
4
This is now saying that I know 16 can be written as 4 equal pieces and I want 3 of those 4 pieces.
How can I break 16 down into 4 equal pieces?
___ โ ___ โ ___ โ ___
What would my answer by if I want 3 out of those 4? ___ โ ___ โ ___ = ___
Advanced Root Definition ๐ ๐ ๐ = ๐ ๐ ๐
#1) What is 27
2
3
?
27 = __ โ __ โ __
Thus, 27
2
3
= __ โ __ = __
#2) Find 2
36
3 ๐๐ ______
36 = __ โ __
Thus, 36
3
2
= ___ โ ___ โ ___ = ___
Practice 3:
What is 64
2
3
?
Practice 4:
Find 5
32
2 ๐๐ ______
How do you feel?
Heads down, thumbs up!
Got it!
Ehh…so, so.
HELP!!! ๏
๏ KAHOOT!
๏ You MUST fill out the exit ticket along with the kahoot to receive participation points for today’s classwork.
๏ Put the exit ticket in the folder that best rates your current understanding of Lesson 7.3!
๏ HOMEWORK – Day 1 Portion of the Worksheet!
• I can solve exponential equations by recognizing how to rewrite expressions in exponential form.
What would x be in the following problems?
We Do: You Do:
Solving Exponential Equations
Power Property of Equality
For any real number ๐ > 0 and ๐ ≠ 1
, then ๐ ๐ฅ = ๐ ๐ฆ if and only if ๐ฅ = ๐ฆ
.
Example 1: If
5 ๐ฅ
= 5
3 , then ๐ฅ = 3
Example 2: If
2 ๐ฅ+1 = 2 7 , then ๐ฅ + 1 = 7
Solving Exponential
Equations
Practice 1:
Solve
6 ๐ฅ = 216
Practice 2:
Solve
25 ๐ฅ−1 = 5
6 ๐ฅ = 6 __
Thus, ๐ฅ = ___
5 = 5
2 ๐ฅ − 1 = 1
2๐ฅ − 2 = 1
Thus, ๐ฅ =
3
2
Solving Exponential
Equations
Practice #3:
Solve
8 ๐ฅ = 512
Practice #4:
Solve
12 2๐ฅ+3 = 144
๏ Day 2 Portion of the Worksheet
๏ Use your time wisely in class because you will also be getting a quiz review worksheet to take home!