Finite Math Examples

Find the Roots (Zeros) 2x^3-x^2-9x-4=0
Step 1
Factor using the rational roots test.
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Step 1.1
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 1.2
Find every combination of . These are the possible roots of the polynomial function.
Step 1.3
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 1.3.1
Substitute into the polynomial.
Step 1.3.2
Raise to the power of .
Step 1.3.3
Multiply by .
Step 1.3.4
Raise to the power of .
Step 1.3.5
Multiply by .
Step 1.3.6
Subtract from .
Step 1.3.7
Multiply by .
Step 1.3.8
Add and .
Step 1.3.9
Subtract from .
Step 1.4
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 1.5
Divide by .
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Step 1.5.1
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 1.5.2
Divide the highest order term in the dividend by the highest order term in divisor .
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Step 1.5.3
Multiply the new quotient term by the divisor.
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Step 1.5.4
The expression needs to be subtracted from the dividend, so change all the signs in
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Step 1.5.5
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
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Step 1.5.6
Pull the next terms from the original dividend down into the current dividend.
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Step 1.5.7
Divide the highest order term in the dividend by the highest order term in divisor .
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Step 1.5.8
Multiply the new quotient term by the divisor.
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Step 1.5.9
The expression needs to be subtracted from the dividend, so change all the signs in
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Step 1.5.10
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
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Step 1.5.11
Pull the next terms from the original dividend down into the current dividend.
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Step 1.5.12
Divide the highest order term in the dividend by the highest order term in divisor .
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Step 1.5.13
Multiply the new quotient term by the divisor.
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Step 1.5.14
The expression needs to be subtracted from the dividend, so change all the signs in
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Step 1.5.15
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
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Step 1.5.16
Since the remander is , the final answer is the quotient.
Step 1.6
Write as a set of factors.
Step 2
If any individual factor on the left side of the equation is equal to , the entire expression will be equal to .
Step 3
Set equal to and solve for .
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Step 3.1
Set equal to .
Step 3.2
Solve for .
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Step 3.2.1
Subtract from both sides of the equation.
Step 3.2.2
Divide each term in by and simplify.
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Step 3.2.2.1
Divide each term in by .
Step 3.2.2.2
Simplify the left side.
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Step 3.2.2.2.1
Cancel the common factor of .
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Step 3.2.2.2.1.1
Cancel the common factor.
Step 3.2.2.2.1.2
Divide by .
Step 3.2.2.3
Simplify the right side.
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Step 3.2.2.3.1
Move the negative in front of the fraction.
Step 4
Set equal to and solve for .
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Step 4.1
Set equal to .
Step 4.2
Solve for .
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Step 4.2.1
Use the quadratic formula to find the solutions.
Step 4.2.2
Substitute the values , , and into the quadratic formula and solve for .
Step 4.2.3
Simplify.
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Step 4.2.3.1
Simplify the numerator.
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Step 4.2.3.1.1
Raise to the power of .
Step 4.2.3.1.2
Multiply .
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Step 4.2.3.1.2.1
Multiply by .
Step 4.2.3.1.2.2
Multiply by .
Step 4.2.3.1.3
Add and .
Step 4.2.3.2
Multiply by .
Step 4.2.4
The final answer is the combination of both solutions.
Step 5
The final solution is all the values that make true.
Step 6
The result can be shown in multiple forms.
Exact Form:
Decimal Form:
Step 7