Sec. 4.6(A) Solving Higher Order Inequalities

4
Sec. 4.6(A) Solving Higher Order Inequalities We will use a new notation for writing inequalities. Interval notation looks like the following: > or < will use ______________ < or > will use ______________ Inequality Notation Graph Interval Notation 2 < x 3 x > 4 x > 2 or x Steps for solving a Higher Order Inequality . 1. 2. 3. 4. open circle ( , ) closed circle [ , ] 2 3 (2 , 3 ] 4 (4 , -2 (- R (- Get a zero on one side of the equation. Find the x-int.’s and graph those one a # line. Pick points in the regions separated by the x-int’s. to test. Write a solution of the graph drawn using interval notation. x 2 3

description

Sec. 4.6(A) Solving Higher Order Inequalities We will use a new notation for writing inequalities. Interval notation looks like the following: > or < will use ______________ < or > will use ______________. o pen circle. c losed circle. ( , ). [ , ]. (2 , 3 ]. - PowerPoint PPT Presentation

Transcript of Sec. 4.6(A) Solving Higher Order Inequalities

Page 1: Sec. 4.6(A)  Solving Higher Order Inequalities

Sec. 4.6(A) Solving Higher Order Inequalities We will use a new notation for writing inequalities.  Interval notation looks like the following:

  > or < will use ______________    <  or  >  will use ______________

Inequality Notation Graph Interval Notation                                               2 <  x     3                                        

                          

                                                       x > 4

   

                   

            x > 2   or x 

 

 

x 2

3

Steps for solving a Higher Order Inequality.

  1.

  2.

  3.

  4.

open circle(   ,   )

closed circle[    ,   ]

2               3(2 , 3 ]

4 (4 , 

-2 (- 

R(- 

Get a zero on one side of the equation.

Find the x-int.’s and graph those one a # line.

Pick points in the regions separated by the x-int’s. to test.

Write a solution of the graph drawn using interval notation.

Page 2: Sec. 4.6(A)  Solving Higher Order Inequalities

Ex1: Solve: x2 - 1 < 0    

 Ex2: Solve: x2 – 4x < 0    

 Ex3: Solve:         x2 + 9 > 0

(x + 1)(x – 1) = 0

x + 1 = 0          x – 1 = 0      x = -1               x = 1

-1                 1 - 1  <  0   4 – 1  <  0      3 < 0

          F

 - 1  < 0    0 – 1  <  0       -1  <  0

          T

 - 1 < 0   4 – 1  < 0       3 < 0

         F

[-1 , 1]

x(x – 4) = 0

x = 0          x – 4 = 0                        x = 4

  0                  4 - 4(-1) < 0         1 + 4 < 0               5 < 0

              F

 - 4(2) < 0     4 – 8 < 0         -4 < 0

            T

 - 4(5) < 0   25 – 20 < 0        5 < 0

           F

(0 , 4)

 + 9 = 0   = -9 = 

2 imaginary answers

(−∞ ,∞ )

Page 3: Sec. 4.6(A)  Solving Higher Order Inequalities

Ex4: (x – 1)(x – 2)(x – 3)  <  0

Ex5: 16x4 – 4x2  >  0    

Ex6: x3 > 8 

x – 1 = 0      x - 2 = 0       x – 3 = 0    x = 1            x = 2             x = 3

1                 2                30 < 0   T

 (0.5)(-0.5)(-1.5) < 0            0.375 < 0

                  F

 < 0           -0.375 < 0

                  T          6 < 0

            F (-

 = 0             (2x + 1)(2x – 1) = 0      = 0                                  x = 0  (D.R.)

             0            -  > 0         16 - 4 > 0             12 > 0

                 T

 -  > 0           0.0625 – 0.25 > 0               -0.1875 > 0

                        F

 -  >  0     0.0625 – 0.25 > 0            -0.1875 > 0

                   F -  > 0         0 – 0 > 0              0 > 0

               T

 -  > 0     16 – 4 > 0           12 > 0

              T

 - 8 > 0

 = 0x – 2 = 0     x = 2

2 > 8  0 > 8

     F

 > 8  27 > 8      T

(𝟐 , ∞ )

Page 4: Sec. 4.6(A)  Solving Higher Order Inequalities

Solve the following using your graphing calculator. Ex8: x2 – 2x – 3  <  0 Ex9:       Ex10:    x3 > 4

 <  0

Ex7: x3 + 4x2 + 4x  <  0

 = 0x (x + 2)(x + 2) = 0

x = 0            x + 2 = 0                          x = -2   (D.R.)

 -2                           0+ 4(-3)  < 0                   -3  < 0

                      T  + 4 + 4(-1)  <  0       -1 + 4 – 4 < 0                   -1 < 0

                        T

 + 4 + 4(1) < 0           1 + 4 + 4 < 0                     9 < 0

                        F

(−∞ ,𝟎 ]

[−𝟏 ,𝟑 ] (−𝟐 ,𝟎 )∪ (𝟎 ,𝟐 )

(𝟏 .𝟓𝟖𝟕 , ∞ )