Trigonometry Examples

Find the Roots (Zeros) x^4+x^3-54x^2+120x=0
Step 1
Factor the left side of the equation.
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Step 1.1
Factor out of .
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Step 1.1.1
Factor out of .
Step 1.1.2
Factor out of .
Step 1.1.3
Factor out of .
Step 1.1.4
Factor out of .
Step 1.1.5
Factor out of .
Step 1.1.6
Factor out of .
Step 1.1.7
Factor out of .
Step 1.2
Factor.
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Step 1.2.1
Factor using the rational roots test.
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Step 1.2.1.1
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 1.2.1.2
Find every combination of . These are the possible roots of the polynomial function.
Step 1.2.1.3
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 1.2.1.3.1
Substitute into the polynomial.
Step 1.2.1.3.2
Raise to the power of .
Step 1.2.1.3.3
Raise to the power of .
Step 1.2.1.3.4
Add and .
Step 1.2.1.3.5
Multiply by .
Step 1.2.1.3.6
Subtract from .
Step 1.2.1.3.7
Add and .
Step 1.2.1.4
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 1.2.1.5
Divide by .
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Step 1.2.1.5.1
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 1.2.1.5.2
Divide the highest order term in the dividend by the highest order term in divisor .
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Step 1.2.1.5.3
Multiply the new quotient term by the divisor.
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Step 1.2.1.5.4
The expression needs to be subtracted from the dividend, so change all the signs in
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Step 1.2.1.5.5
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
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Step 1.2.1.5.6
Pull the next terms from the original dividend down into the current dividend.
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Step 1.2.1.5.7
Divide the highest order term in the dividend by the highest order term in divisor .
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Step 1.2.1.5.8
Multiply the new quotient term by the divisor.
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Step 1.2.1.5.9
The expression needs to be subtracted from the dividend, so change all the signs in
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Step 1.2.1.5.10
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
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Step 1.2.1.5.11
Pull the next terms from the original dividend down into the current dividend.
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Step 1.2.1.5.12
Divide the highest order term in the dividend by the highest order term in divisor .
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Step 1.2.1.5.13
Multiply the new quotient term by the divisor.
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Step 1.2.1.5.14
The expression needs to be subtracted from the dividend, so change all the signs in
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Step 1.2.1.5.15
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
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Step 1.2.1.5.16
Since the remander is , the final answer is the quotient.
Step 1.2.1.6
Write as a set of factors.
Step 1.2.2
Remove unnecessary parentheses.
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 .
Step 4
Set equal to and solve for .
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Step 4.1
Set equal to .
Step 4.2
Add to both sides of the equation.
Step 5
Set equal to and solve for .
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Step 5.1
Set equal to .
Step 5.2
Solve for .
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Step 5.2.1
Use the quadratic formula to find the solutions.
Step 5.2.2
Substitute the values , , and into the quadratic formula and solve for .
Step 5.2.3
Simplify.
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Step 5.2.3.1
Simplify the numerator.
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Step 5.2.3.1.1
Raise to the power of .
Step 5.2.3.1.2
Multiply .
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Step 5.2.3.1.2.1
Multiply by .
Step 5.2.3.1.2.2
Multiply by .
Step 5.2.3.1.3
Add and .
Step 5.2.3.1.4
Rewrite as .
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Step 5.2.3.1.4.1
Factor out of .
Step 5.2.3.1.4.2
Rewrite as .
Step 5.2.3.1.5
Pull terms out from under the radical.
Step 5.2.3.2
Multiply by .
Step 5.2.3.3
Simplify .
Step 5.2.4
The final answer is the combination of both solutions.
Step 6
The final solution is all the values that make true.
Step 7
The result can be shown in multiple forms.
Exact Form:
Decimal Form:
Step 8