Finite Math Examples

Find the Roots/Zeros Using the Rational Roots Test x^6-x^5-5x^4+5x^3-36x^2+36x
Step 1
If a polynomial function has integer coefficients, then every rational zero will have the form where is a factor of the constant and is a factor of the leading coefficient.
Step 2
Find every combination of . These are the possible roots of the polynomial function.
Step 3
Substitute the possible roots one by one into the polynomial to find the actual roots. Simplify to check if the value is , which means it is a root.
Step 4
Simplify the expression. In this case, the expression is equal to so is a root of the polynomial.
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Step 4.1
Simplify each term.
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Step 4.1.1
Raising to any positive power yields .
Step 4.1.2
Raising to any positive power yields .
Step 4.1.3
Multiply by .
Step 4.1.4
Raising to any positive power yields .
Step 4.1.5
Multiply by .
Step 4.1.6
Raising to any positive power yields .
Step 4.1.7
Multiply by .
Step 4.1.8
Raising to any positive power yields .
Step 4.1.9
Multiply by .
Step 4.1.10
Multiply by .
Step 4.2
Simplify by adding numbers.
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Step 4.2.1
Add and .
Step 4.2.2
Add and .
Step 4.2.3
Add and .
Step 4.2.4
Add and .
Step 4.2.5
Add and .
Step 5
Since is a known root, divide the polynomial by to find the quotient polynomial. This polynomial can then be used to find the remaining roots.
Step 6
Next, find the roots of the remaining polynomial. The order of the polynomial has been reduced by .
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Step 6.1
Place the numbers representing the divisor and the dividend into a division-like configuration.
  
Step 6.2
The first number in the dividend is put into the first position of the result area (below the horizontal line).
  
Step 6.3
Multiply the newest entry in the result by the divisor and place the result of under the next term in the dividend .
  
Step 6.4
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
  
Step 6.5
Multiply the newest entry in the result by the divisor and place the result of under the next term in the dividend .
  
Step 6.6
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
  
Step 6.7
Multiply the newest entry in the result by the divisor and place the result of under the next term in the dividend .
  
Step 6.8
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
  
Step 6.9
Multiply the newest entry in the result by the divisor and place the result of under the next term in the dividend .
  
Step 6.10
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
  
Step 6.11
Multiply the newest entry in the result by the divisor and place the result of under the next term in the dividend .
  
Step 6.12
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
  
Step 6.13
Multiply the newest entry in the result by the divisor and place the result of under the next term in the dividend .
 
Step 6.14
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
 
Step 6.15
All numbers except the last become the coefficients of the quotient polynomial. The last value in the result line is the remainder.
Step 6.16
Simplify the quotient polynomial.
Step 7
Solve the equation to find any remaining roots.
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Step 7.1
Factor the left side of the equation.
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Step 7.1.1
Regroup terms.
Step 7.1.2
Factor out of .
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Step 7.1.2.1
Factor out of .
Step 7.1.2.2
Factor out of .
Step 7.1.2.3
Factor out of .
Step 7.1.2.4
Factor out of .
Step 7.1.2.5
Factor out of .
Step 7.1.3
Rewrite as .
Step 7.1.4
Let . Substitute for all occurrences of .
Step 7.1.5
Factor using the AC method.
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Step 7.1.5.1
Consider the form . Find a pair of integers whose product is and whose sum is . In this case, whose product is and whose sum is .
Step 7.1.5.2
Write the factored form using these integers.
Step 7.1.6
Replace all occurrences of with .
Step 7.1.7
Rewrite as .
Step 7.1.8
Factor.
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Step 7.1.8.1
Since both terms are perfect squares, factor using the difference of squares formula, where and .
Step 7.1.8.2
Remove unnecessary parentheses.
Step 7.1.9
Rewrite as .
Step 7.1.10
Let . Substitute for all occurrences of .
Step 7.1.11
Factor by grouping.
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Step 7.1.11.1
For a polynomial of the form , rewrite the middle term as a sum of two terms whose product is and whose sum is .
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Step 7.1.11.1.1
Factor out of .
Step 7.1.11.1.2
Rewrite as plus
Step 7.1.11.1.3
Apply the distributive property.
Step 7.1.11.2
Factor out the greatest common factor from each group.
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Step 7.1.11.2.1
Group the first two terms and the last two terms.
Step 7.1.11.2.2
Factor out the greatest common factor (GCF) from each group.
Step 7.1.11.3
Factor the polynomial by factoring out the greatest common factor, .
Step 7.1.12
Replace all occurrences of with .
Step 7.1.13
Rewrite as .
Step 7.1.14
Factor.
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Step 7.1.14.1
Since both terms are perfect squares, factor using the difference of squares formula, where and .
Step 7.1.14.2
Remove unnecessary parentheses.
Step 7.1.15
Factor out of .
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Step 7.1.15.1
Factor out of .
Step 7.1.15.2
Factor out of .
Step 7.1.15.3
Factor out of .
Step 7.1.16
Apply the distributive property.
Step 7.1.17
Multiply by by adding the exponents.
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Step 7.1.17.1
Multiply by .
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Step 7.1.17.1.1
Raise to the power of .
Step 7.1.17.1.2
Use the power rule to combine exponents.
Step 7.1.17.2
Add and .
Step 7.1.18
Move to the left of .
Step 7.1.19
Reorder terms.
Step 7.1.20
Factor.
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Step 7.1.20.1
Rewrite in a factored form.
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Step 7.1.20.1.1
Factor out the greatest common factor from each group.
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Step 7.1.20.1.1.1
Group the first two terms and the last two terms.
Step 7.1.20.1.1.2
Factor out the greatest common factor (GCF) from each group.
Step 7.1.20.1.2
Factor the polynomial by factoring out the greatest common factor, .
Step 7.1.20.2
Remove unnecessary parentheses.
Step 7.2
If any individual factor on the left side of the equation is equal to , the entire expression will be equal to .
Step 7.3
Set equal to and solve for .
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Step 7.3.1
Set equal to .
Step 7.3.2
Subtract from both sides of the equation.
Step 7.4
Set equal to and solve for .
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Step 7.4.1
Set equal to .
Step 7.4.2
Add to both sides of the equation.
Step 7.5
Set equal to and solve for .
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Step 7.5.1
Set equal to .
Step 7.5.2
Add to both sides of the equation.
Step 7.6
Set equal to and solve for .
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Step 7.6.1
Set equal to .
Step 7.6.2
Solve for .
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Step 7.6.2.1
Subtract from both sides of the equation.
Step 7.6.2.2
Take the specified root of both sides of the equation to eliminate the exponent on the left side.
Step 7.6.2.3
Simplify .
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Step 7.6.2.3.1
Rewrite as .
Step 7.6.2.3.2
Rewrite as .
Step 7.6.2.3.3
Rewrite as .
Step 7.6.2.3.4
Rewrite as .
Step 7.6.2.3.5
Pull terms out from under the radical, assuming positive real numbers.
Step 7.6.2.3.6
Move to the left of .
Step 7.6.2.4
The complete solution is the result of both the positive and negative portions of the solution.
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Step 7.6.2.4.1
First, use the positive value of the to find the first solution.
Step 7.6.2.4.2
Next, use the negative value of the to find the second solution.
Step 7.6.2.4.3
The complete solution is the result of both the positive and negative portions of the solution.
Step 7.7
The final solution is all the values that make true.
Step 8
The polynomial can be written as a set of linear factors.
Step 9
These are the roots (zeros) of the polynomial .
Step 10