Question
Solve the inequality
x∈(−22,0)∪(0,22)
Evaluate
∣x×1∣>2x3
Any expression multiplied by 1 remains the same
∣x∣>2x3
Move the expression to the left side
∣x∣−2x3>0
Separate the inequality into 4 possible cases
x−2x3>0,x≥0,x3≥0x−2(−x3)>0,x≥0,x3<0−x−2x3>0,x<0,x3≥0−x−2(−x3)>0,x<0,x3<0
Evaluate
More Steps

Evaluate
x−2x3>0
Factor the expression
x(1−2x2)>0
Separate the inequality into 2 possible cases
{x>01−2x2>0{x<01−2x2<0
Solve the inequality
More Steps

Evaluate
1−2x2>0
Rewrite the expression
−2x2>−1
Change the signs on both sides of the inequality and flip the inequality sign
2x2<1
Divide both sides
22x2<21
Divide the numbers
x2<21
Take the 2-th root on both sides of the inequality
x2<21
Calculate
∣x∣<22
Separate the inequality into 2 possible cases
{x<22x>−22
Find the intersection
−22<x<22
{x>0−22<x<22{x<01−2x2<0
Solve the inequality
More Steps

Evaluate
1−2x2<0
Rewrite the expression
−2x2<−1
Change the signs on both sides of the inequality and flip the inequality sign
2x2>1
Divide both sides
22x2>21
Divide the numbers
x2>21
Take the 2-th root on both sides of the inequality
x2>21
Calculate
∣x∣>22
Separate the inequality into 2 possible cases
x>22x<−22
Find the union
x∈(−∞,−22)∪(22,+∞)
{x>0−22<x<22{x<0x∈(−∞,−22)∪(22,+∞)
Find the intersection
0<x<22{x<0x∈(−∞,−22)∪(22,+∞)
Find the intersection
0<x<22x<−22
Find the union
x∈(−∞,−22)∪(0,22)
x∈(−∞,−22)∪(0,22),x≥0,x3≥0x−2(−x3)>0,x≥0,x3<0−x−2x3>0,x<0,x3≥0−x−2(−x3)>0,x<0,x3<0
The only way a base raised to an odd power can be greater than or equal to 0 is if the base is greater than or equal to 0
x∈(−∞,−22)∪(0,22),x≥0,x≥0x−2(−x3)>0,x≥0,x3<0−x−2x3>0,x<0,x3≥0−x−2(−x3)>0,x<0,x3<0
Evaluate
More Steps

Evaluate
x−2(−x3)>0
Simplify the expression
x+2x3>0
Factor the expression
x(1+2x2)>0
Separate the inequality into 2 possible cases
{x>01+2x2>0{x<01+2x2<0
Since the left-hand side is always positive,and the right-hand side is always 0,the statement is true for any value of x
{x>0x∈R{x<01+2x2<0
Since the left-hand side is always positive,and the right-hand side is always 0,the statement is false for any value of x
{x>0x∈R{x<0x∈/R
Find the intersection
x>0{x<0x∈/R
Find the intersection
x>0x∈/R
Find the union
x>0
x∈(−∞,−22)∪(0,22),x≥0,x≥0x>0,x≥0,x3<0−x−2x3>0,x<0,x3≥0−x−2(−x3)>0,x<0,x3<0
The only way a base raised to an odd power can be less than 0 is if the base is less than 0
x∈(−∞,−22)∪(0,22),x≥0,x≥0x>0,x≥0,x<0−x−2x3>0,x<0,x3≥0−x−2(−x3)>0,x<0,x3<0
Evaluate
More Steps

Evaluate
−x−2x3>0
Factor the expression
−x(1+2x2)>0
Divide both sides
x(1+2x2)<0
Separate the inequality into 2 possible cases
{x>01+2x2<0{x<01+2x2>0
Since the left-hand side is always positive,and the right-hand side is always 0,the statement is false for any value of x
{x>0x∈/R{x<01+2x2>0
Since the left-hand side is always positive,and the right-hand side is always 0,the statement is true for any value of x
{x>0x∈/R{x<0x∈R
Find the intersection
x∈/R{x<0x∈R
Find the intersection
x∈/Rx<0
Find the union
x<0
x∈(−∞,−22)∪(0,22),x≥0,x≥0x>0,x≥0,x<0x<0,x<0,x3≥0−x−2(−x3)>0,x<0,x3<0
The only way a base raised to an odd power can be greater than or equal to 0 is if the base is greater than or equal to 0
x∈(−∞,−22)∪(0,22),x≥0,x≥0x>0,x≥0,x<0x<0,x<0,x≥0−x−2(−x3)>0,x<0,x3<0
Evaluate
More Steps

Evaluate
−x−2(−x3)>0
Simplify the expression
−x+2x3>0
Factor the expression
x(−1+2x2)>0
Separate the inequality into 2 possible cases
{x>0−1+2x2>0{x<0−1+2x2<0
Solve the inequality
More Steps

Evaluate
−1+2x2>0
Rewrite the expression
2x2>1
Divide both sides
22x2>21
Divide the numbers
x2>21
Take the 2-th root on both sides of the inequality
x2>21
Calculate
∣x∣>22
Separate the inequality into 2 possible cases
x>22x<−22
Find the union
x∈(−∞,−22)∪(22,+∞)
{x>0x∈(−∞,−22)∪(22,+∞){x<0−1+2x2<0
Solve the inequality
More Steps

Evaluate
−1+2x2<0
Rewrite the expression
2x2<1
Divide both sides
22x2<21
Divide the numbers
x2<21
Take the 2-th root on both sides of the inequality
x2<21
Calculate
∣x∣<22
Separate the inequality into 2 possible cases
{x<22x>−22
Find the intersection
−22<x<22
{x>0x∈(−∞,−22)∪(22,+∞){x<0−22<x<22
Find the intersection
x>22{x<0−22<x<22
Find the intersection
x>22−22<x<0
Find the union
x∈(−22,0)∪(22,+∞)
x∈(−∞,−22)∪(0,22),x≥0,x≥0x>0,x≥0,x<0x<0,x<0,x≥0x∈(−22,0)∪(22,+∞),x<0,x3<0
The only way a base raised to an odd power can be less than 0 is if the base is less than 0
x∈(−∞,−22)∪(0,22),x≥0,x≥0x>0,x≥0,x<0x<0,x<0,x≥0x∈(−22,0)∪(22,+∞),x<0,x<0
Find the intersection
0<x<22x>0,x≥0,x<0x<0,x<0,x≥0x∈(−22,0)∪(22,+∞),x<0,x<0
Find the intersection
0<x<22x∈∅x<0,x<0,x≥0x∈(−22,0)∪(22,+∞),x<0,x<0
Find the intersection
0<x<22x∈∅x∈∅x∈(−22,0)∪(22,+∞),x<0,x<0
Find the intersection
0<x<22x∈∅x∈∅−22<x<0
Solution
x∈(−22,0)∪(0,22)
Show Solution
