2. to solve inequalities that involve radical
functions
3. A radical function looks like
n y
radicant
index
When , we have a square root fuction.
n 2
n 3
When , we have a cube root function.
When , we have a fourth root function.
n 4
When n 5
, we have a fifth root function,
and so on…
4. Given a radical function ,
Case 1:
If n is even, then and
Case 2:
If n is odd, then and
Furthermore,
n y
0 n y 0y
n y R yR
n
n y y
5. Which of the following equations does not
have a solution? Why?
Because
x 2 0
6. What can you say about the solutions of the
following inequalities?
4
8
x
3 5
2
3
x
x
2 4
2
7. Do the following inequalities have solutions?
What is the lower bound for each of the
inequalities?
4
3 5
3
1 3
x
x
x
x
0 3
5
4
x
0
3
x
0 1
3
Solve the inequalities.
8. Suppose the following inequalities are valid,
then what must be true about each of the
inequalities?
4 2
6
x x
6 5
3 6
1
x
x
4 2
6
x x
6 0
3 0
0
x
x
Solve the inequalities.
9. Let’s solve the following inequalities
4
2 3 3
3 2 5
2 4
2
x
x
x
x
10. Up until now, we have discussed the fact
that for
Case 1:
If
k
f x g x
a if g x then
b if g x and f x then f x g x
Case 2:
If
n 2k
2
2
( ) ( )
( ) ( ) 0,
( ) ( ) 0 ( ) 0, ( ) k
( )
2
k
f ( x ) g ( x
)
a if g x then f x
b if g x then f x g 2
x
( ) ( ) 0, ( ) 0
( ) ( ) 0, ( ) k
( )
11. Do you remember the fact that if ,
then and ?
n yR y R
Because of this, we have less rules for solving
inequalities whose index is odd.
In fact,
n 2k 1
k k
2 1 2
1
f x g x f x g x
( ) ( ) ( )
( )
k k
2 1 2
1
f x g x f x g x
( ) ( ) ( )
( )
12. Solve each of the following inequalities whose
index is odd.
3
2 2
3
9 2
1 2
3
1
1
x
x
x
x
Answers:
[1, )
( 14, 14)
1
0,
2
x