Precalculus Examples

Split Using Partial Fraction Decomposition (4x^3+5^2+7x-1)/(x^2x+1)
Step 1
Decompose the fraction and multiply through by the common denominator.
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Step 1.1
Factor the fraction.
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Step 1.1.1
Raise to the power of .
Step 1.1.2
Subtract from .
Step 1.1.3
Factor using the rational roots test.
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Step 1.1.3.1
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 1.1.3.2
Find every combination of . These are the possible roots of the polynomial function.
Step 1.1.3.3
Substitute and simplify the expression. In this case, the expression is equal to so is a root of the polynomial.
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Step 1.1.3.3.1
Substitute into the polynomial.
Step 1.1.3.3.2
Raise to the power of .
Step 1.1.3.3.3
Multiply by .
Step 1.1.3.3.4
Multiply by .
Step 1.1.3.3.5
Subtract from .
Step 1.1.3.3.6
Add and .
Step 1.1.3.4
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 1.1.3.5
Divide by .
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Step 1.1.3.5.1
Set up the polynomials to be divided. If there is not a term for every exponent, insert one with a value of .
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Step 1.1.3.5.2
Divide the highest order term in the dividend by the highest order term in divisor .
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Step 1.1.3.5.3
Multiply the new quotient term by the divisor.
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Step 1.1.3.5.4
The expression needs to be subtracted from the dividend, so change all the signs in
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Step 1.1.3.5.5
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
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Step 1.1.3.5.6
Pull the next terms from the original dividend down into the current dividend.
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Step 1.1.3.5.7
Divide the highest order term in the dividend by the highest order term in divisor .
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Step 1.1.3.5.8
Multiply the new quotient term by the divisor.
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Step 1.1.3.5.9
The expression needs to be subtracted from the dividend, so change all the signs in
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Step 1.1.3.5.10
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
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+
Step 1.1.3.5.11
Pull the next terms from the original dividend down into the current dividend.
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Step 1.1.3.5.12
Divide the highest order term in the dividend by the highest order term in divisor .
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Step 1.1.3.5.13
Multiply the new quotient term by the divisor.
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Step 1.1.3.5.14
The expression needs to be subtracted from the dividend, so change all the signs in
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--
Step 1.1.3.5.15
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
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Step 1.1.3.5.16
Since the remander is , the final answer is the quotient.
Step 1.1.3.6
Write as a set of factors.
Step 1.1.4
Multiply by by adding the exponents.
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Step 1.1.4.1
Multiply by .
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Step 1.1.4.1.1
Raise to the power of .
Step 1.1.4.1.2
Use the power rule to combine exponents.
Step 1.1.4.2
Add and .
Step 1.1.5
Rewrite as .
Step 1.1.6
Since both terms are perfect cubes, factor using the sum of cubes formula, where and .
Step 1.1.7
Simplify.
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Step 1.1.7.1
Multiply by .
Step 1.1.7.2
One to any power is one.
Step 1.2
For each factor in the denominator, create a new fraction using the factor as the denominator, and an unknown value as the numerator. Since the factor in the denominator is linear, put a single variable in its place .
Step 1.3
For each factor in the denominator, create a new fraction using the factor as the denominator, and an unknown value as the numerator. Since the factor is 2nd order, terms are required in the numerator. The number of terms required in the numerator is always equal to the order of the factor in the denominator.
Step 1.4
Multiply each fraction in the equation by the denominator of the original expression. In this case, the denominator is .
Step 1.5
Reduce the expression by cancelling the common factors.
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Step 1.5.1
Cancel the common factor of .
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Step 1.5.1.1
Cancel the common factor.
Step 1.5.1.2
Rewrite the expression.
Step 1.5.2
Cancel the common factor of .
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Step 1.5.2.1
Cancel the common factor.
Step 1.5.2.2
Divide by .
Step 1.6
Expand by multiplying each term in the first expression by each term in the second expression.
Step 1.7
Simplify terms.
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Step 1.7.1
Simplify each term.
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Step 1.7.1.1
Rewrite using the commutative property of multiplication.
Step 1.7.1.2
Multiply by by adding the exponents.
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Step 1.7.1.2.1
Move .
Step 1.7.1.2.2
Multiply by .
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Step 1.7.1.2.2.1
Raise to the power of .
Step 1.7.1.2.2.2
Use the power rule to combine exponents.
Step 1.7.1.2.3
Add and .
Step 1.7.1.3
Multiply by .
Step 1.7.1.4
Rewrite using the commutative property of multiplication.
Step 1.7.1.5
Multiply by by adding the exponents.
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Step 1.7.1.5.1
Move .
Step 1.7.1.5.2
Multiply by .
Step 1.7.1.6
Multiply by .
Step 1.7.1.7
Multiply by .
Step 1.7.1.8
Multiply by .
Step 1.7.1.9
Multiply by .
Step 1.7.1.10
Multiply by .
Step 1.7.2
Simplify by adding terms.
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Step 1.7.2.1
Combine the opposite terms in .
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Step 1.7.2.1.1
Add and .
Step 1.7.2.1.2
Add and .
Step 1.7.2.2
Subtract from .
Step 1.8
Simplify each term.
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Step 1.8.1
Cancel the common factor of .
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Step 1.8.1.1
Cancel the common factor.
Step 1.8.1.2
Divide by .
Step 1.8.2
Apply the distributive property.
Step 1.8.3
Simplify.
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Step 1.8.3.1
Rewrite using the commutative property of multiplication.
Step 1.8.3.2
Multiply by .
Step 1.8.4
Cancel the common factor of .
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Step 1.8.4.1
Cancel the common factor.
Step 1.8.4.2
Divide by .
Step 1.8.5
Expand using the FOIL Method.
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Step 1.8.5.1
Apply the distributive property.
Step 1.8.5.2
Apply the distributive property.
Step 1.8.5.3
Apply the distributive property.
Step 1.8.6
Simplify each term.
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Step 1.8.6.1
Multiply by by adding the exponents.
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Step 1.8.6.1.1
Move .
Step 1.8.6.1.2
Multiply by .
Step 1.8.6.2
Multiply by .
Step 1.8.6.3
Multiply by .
Step 1.9
Simplify the expression.
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Step 1.9.1
Move .
Step 1.9.2
Reorder and .
Step 1.9.3
Reorder and .
Step 1.9.4
Move .
Step 1.9.5
Move .
Step 2
Create equations for the partial fraction variables and use them to set up a system of equations.
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Step 2.1
Create an equation for the partial fraction variables by equating the coefficients of from each side of the equation. For the equation to be equal, the equivalent coefficients on each side of the equation must be equal.
Step 2.2
Create an equation for the partial fraction variables by equating the coefficients of from each side of the equation. For the equation to be equal, the equivalent coefficients on each side of the equation must be equal.
Step 2.3
Create an equation for the partial fraction variables by equating the coefficients of the terms not containing . For the equation to be equal, the equivalent coefficients on each side of the equation must be equal.
Step 2.4
Set up the system of equations to find the coefficients of the partial fractions.
Step 3
Solve the system of equations.
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Step 3.1
Solve for in .
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Step 3.1.1
Rewrite the equation as .
Step 3.1.2
Subtract from both sides of the equation.
Step 3.2
Replace all occurrences of with in each equation.
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Step 3.2.1
Replace all occurrences of in with .
Step 3.2.2
Simplify the right side.
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Step 3.2.2.1
Simplify .
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Step 3.2.2.1.1
Multiply .
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Step 3.2.2.1.1.1
Multiply by .
Step 3.2.2.1.1.2
Multiply by .
Step 3.2.2.1.2
Add and .
Step 3.2.3
Replace all occurrences of in with .
Step 3.2.4
Simplify the right side.
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Step 3.2.4.1
Remove parentheses.
Step 3.3
Solve for in .
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Step 3.3.1
Rewrite the equation as .
Step 3.3.2
Add to both sides of the equation.
Step 3.4
Replace all occurrences of with in each equation.
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Step 3.4.1
Replace all occurrences of in with .
Step 3.4.2
Simplify .
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Step 3.4.2.1
Simplify the left side.
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Step 3.4.2.1.1
Remove parentheses.
Step 3.4.2.2
Simplify the right side.
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Step 3.4.2.2.1
Add and .
Step 3.5
Solve for in .
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Step 3.5.1
Rewrite the equation as .
Step 3.5.2
Move all terms not containing to the right side of the equation.
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Step 3.5.2.1
Subtract from both sides of the equation.
Step 3.5.2.2
Subtract from .
Step 3.5.3
Divide each term in by and simplify.
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Step 3.5.3.1
Divide each term in by .
Step 3.5.3.2
Simplify the left side.
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Step 3.5.3.2.1
Cancel the common factor of .
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Step 3.5.3.2.1.1
Cancel the common factor.
Step 3.5.3.2.1.2
Divide by .
Step 3.5.3.3
Simplify the right side.
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Step 3.5.3.3.1
Move the negative in front of the fraction.
Step 3.6
Replace all occurrences of with in each equation.
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Step 3.6.1
Replace all occurrences of in with .
Step 3.6.2
Simplify .
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Step 3.6.2.1
Simplify the left side.
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Step 3.6.2.1.1
Remove parentheses.
Step 3.6.2.2
Simplify the right side.
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Step 3.6.2.2.1
Simplify .
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Step 3.6.2.2.1.1
To write as a fraction with a common denominator, multiply by .
Step 3.6.2.2.1.2
Combine and .
Step 3.6.2.2.1.3
Combine the numerators over the common denominator.
Step 3.6.2.2.1.4
Simplify the numerator.
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Step 3.6.2.2.1.4.1
Multiply by .
Step 3.6.2.2.1.4.2
Subtract from .
Step 3.6.3
Replace all occurrences of in with .
Step 3.6.4
Simplify the right side.
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Step 3.6.4.1
Multiply .
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Step 3.6.4.1.1
Multiply by .
Step 3.6.4.1.2
Multiply by .
Step 3.7
List all of the solutions.
Step 4
Replace each of the partial fraction coefficients in with the values found for , , and .
Step 5
Simplify each term.
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Step 5.1
Combine and .
Step 5.2
Move to the left of .