Question
Solve the inequality
Solve the inequality by testing the values in the interval
Solve for x
x∈(−∞,−210)∪(210,+∞)
Evaluate
xx3−2>21
Find the domain
xx3−2>21,x=0
Divide the terms
More Steps

Evaluate
xx3
Use the product rule aman=an−m to simplify the expression
1x3−1
Simplify
x3−1
Divide the terms
x2
x2−2>21
Move the expression to the left side
x2−2−21>0
Subtract the numbers
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Evaluate
−2−21
Reduce fractions to a common denominator
−22×2−21
Write all numerators above the common denominator
2−2×2−1
Multiply the numbers
2−4−1
Subtract the numbers
2−5
Use b−a=−ba=−ba to rewrite the fraction
−25
x2−25>0
Rewrite the expression
x2−25=0
Move the constant to the right-hand side and change its sign
x2=0+25
Add the terms
x2=25
Take the root of both sides of the equation and remember to use both positive and negative roots
x=±25
Simplify the expression
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Evaluate
25
To take a root of a fraction,take the root of the numerator and denominator separately
25
Multiply by the Conjugate
2×25×2
Multiply the numbers
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Evaluate
5×2
The product of roots with the same index is equal to the root of the product
5×2
Calculate the product
10
2×210
When a square root of an expression is multiplied by itself,the result is that expression
210
x=±210
Separate the equation into 2 possible cases
x=210x=−210
Determine the test intervals using the critical values
x<−210−210<x<210x>210
Choose a value form each interval
x1=−3x2=0x3=3
To determine if x<−210 is the solution to the inequality,test if the chosen value x=−3 satisfies the initial inequality
More Steps

Evaluate
(−3)2−2>21
Subtract the numbers
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Evaluate
(−3)2−2
Simplify
32−2
Evaluate the power
9−2
Subtract the numbers
7
7>21
Calculate
7>0.5
Check the inequality
true
x<−210 is the solutionx2=0x3=3
To determine if −210<x<210 is the solution to the inequality,test if the chosen value x=0 satisfies the initial inequality
More Steps

Evaluate
02−2>21
Simplify
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Evaluate
02−2
Calculate
0−2
Removing 0 doesn't change the value,so remove it from the expression
−2
−2>21
Calculate
−2>0.5
Check the inequality
false
x<−210 is the solution−210<x<210 is not a solutionx3=3
To determine if x>210 is the solution to the inequality,test if the chosen value x=3 satisfies the initial inequality
More Steps

Evaluate
32−2>21
Subtract the numbers
More Steps

Evaluate
32−2
Evaluate the power
9−2
Subtract the numbers
7
7>21
Calculate
7>0.5
Check the inequality
true
x<−210 is the solution−210<x<210 is not a solutionx>210 is the solution
The original inequality is a strict inequality,so does not include the critical value ,the final solution is x∈(−∞,−210)∪(210,+∞)
x∈(−∞,−210)∪(210,+∞)
Check if the solution is in the defined range
x∈(−∞,−210)∪(210,+∞),x=0
Solution
x∈(−∞,−210)∪(210,+∞)
Show Solution
