Solution - Finding the roots of polynomials
Other Ways to Solve
Finding the roots of polynomialsStep by Step Solution
Step 1 :
9
Simplify ——
v2
Equation at the end of step 1 :
9 ((((3•(v2))-6v)-——)-9v)+18 v2Step 2 :
Equation at the end of step 2 :
9
(((3v2 - 6v) - ——) - 9v) + 18
v2
Step 3 :
Rewriting the whole as an Equivalent Fraction :
3.1 Subtracting a fraction from a whole
Rewrite the whole as a fraction using v2 as the denominator :
3v2 - 6v (3v2 - 6v) • v2
3v2 - 6v = ———————— = ———————————————
1 v2
Equivalent fraction : The fraction thus generated looks different but has the same value as the whole
Common denominator : The equivalent fraction and the other fraction involved in the calculation share the same denominator
Step 4 :
Pulling out like terms :
4.1 Pull out like factors :
3v2 - 6v = 3v • (v - 2)
Adding fractions that have a common denominator :
4.2 Adding up the two equivalent fractions
Add the two equivalent fractions which now have a common denominator
Combine the numerators together, put the sum or difference over the common denominator then reduce to lowest terms if possible:
3v • (v-2) • v2 - (9) 3v4 - 6v3 - 9
————————————————————— = —————————————
v2 v2
Equation at the end of step 4 :
(3v4 - 6v3 - 9)
(——————————————— - 9v) + 18
v2
Step 5 :
Rewriting the whole as an Equivalent Fraction :
5.1 Subtracting a whole from a fraction
Rewrite the whole as a fraction using v2 as the denominator :
9v 9v • v2
9v = —— = ———————
1 v2
Step 6 :
Pulling out like terms :
6.1 Pull out like factors :
3v4 - 6v3 - 9 = 3 • (v4 - 2v3 - 3)
Polynomial Roots Calculator :
6.2 Find roots (zeroes) of : F(v) = v4 - 2v3 - 3
Polynomial Roots Calculator is a set of methods aimed at finding values of v for which F(v)=0
Rational Roots Test is one of the above mentioned tools. It would only find Rational Roots that is numbers v which can be expressed as the quotient of two integers
The Rational Root Theorem states that if a polynomial zeroes for a rational number P/Q then P is a factor of the Trailing Constant and Q is a factor of the Leading Coefficient
In this case, the Leading Coefficient is 1 and the Trailing Constant is -3.
The factor(s) are:
of the Leading Coefficient : 1
of the Trailing Constant : 1 ,3
Let us test ....
| P | Q | P/Q | F(P/Q) | Divisor | |||||
|---|---|---|---|---|---|---|---|---|---|
| -1 | 1 | -1.00 | 0.00 | v + 1 | |||||
| -3 | 1 | -3.00 | 132.00 | ||||||
| 1 | 1 | 1.00 | -4.00 | ||||||
| 3 | 1 | 3.00 | 24.00 |
The Factor Theorem states that if P/Q is root of a polynomial then this polynomial can be divided by q*x-p Note that q and p originate from P/Q reduced to its lowest terms
In our case this means that
v4 - 2v3 - 3
can be divided with v + 1
Polynomial Long Division :
6.3 Polynomial Long Division
Dividing : v4 - 2v3 - 3
("Dividend")
By : v + 1 ("Divisor")
| dividend | v4 | - | 2v3 | - | 3 | ||||||
| - divisor | * v3 | v4 | + | v3 | |||||||
| remainder | - | 3v3 | - | 3 | |||||||
| - divisor | * -3v2 | - | 3v3 | - | 3v2 | ||||||
| remainder | 3v2 | - | 3 | ||||||||
| - divisor | * 3v1 | 3v2 | + | 3v | |||||||
| remainder | - | 3v | - | 3 | |||||||
| - divisor | * -3v0 | - | 3v | - | 3 | ||||||
| remainder | 0 |
Quotient : v3-3v2+3v-3 Remainder: 0
Polynomial Roots Calculator :
6.4 Find roots (zeroes) of : F(v) = v3-3v2+3v-3
See theory in step 6.2
In this case, the Leading Coefficient is 1 and the Trailing Constant is -3.
The factor(s) are:
of the Leading Coefficient : 1
of the Trailing Constant : 1 ,3
Let us test ....
| P | Q | P/Q | F(P/Q) | Divisor | |||||
|---|---|---|---|---|---|---|---|---|---|
| -1 | 1 | -1.00 | -10.00 | ||||||
| -3 | 1 | -3.00 | -66.00 | ||||||
| 1 | 1 | 1.00 | -2.00 | ||||||
| 3 | 1 | 3.00 | 6.00 |
Polynomial Roots Calculator found no rational roots
Adding fractions that have a common denominator :
6.5 Adding up the two equivalent fractions
3 • (v3-3v2+3v-3) • (v+1) - (9v • v2) 3v4 - 15v3 - 9
————————————————————————————————————— = ——————————————
v2 v2
Equation at the end of step 6 :
(3v4 - 15v3 - 9)
———————————————— + 18
v2
Step 7 :
Rewriting the whole as an Equivalent Fraction :
7.1 Adding a whole to a fraction
Rewrite the whole as a fraction using v2 as the denominator :
18 18 • v2
18 = —— = ———————
1 v2
Step 8 :
Pulling out like terms :
8.1 Pull out like factors :
3v4 - 15v3 - 9 = 3 • (v4 - 5v3 - 3)
Polynomial Roots Calculator :
8.2 Find roots (zeroes) of : F(v) = v4 - 5v3 - 3
See theory in step 6.2
In this case, the Leading Coefficient is 1 and the Trailing Constant is -3.
The factor(s) are:
of the Leading Coefficient : 1
of the Trailing Constant : 1 ,3
Let us test ....
| P | Q | P/Q | F(P/Q) | Divisor | |||||
|---|---|---|---|---|---|---|---|---|---|
| -1 | 1 | -1.00 | 3.00 | ||||||
| -3 | 1 | -3.00 | 213.00 | ||||||
| 1 | 1 | 1.00 | -7.00 | ||||||
| 3 | 1 | 3.00 | -57.00 |
Polynomial Roots Calculator found no rational roots
Adding fractions that have a common denominator :
8.3 Adding up the two equivalent fractions
3 • (v4-5v3-3) + 18 • v2 3v4 - 15v3 + 18v2 - 9
———————————————————————— = —————————————————————
v2 v2
Step 9 :
Pulling out like terms :
9.1 Pull out like factors :
3v4 - 15v3 + 18v2 - 9 =
3 • (v4 - 5v3 + 6v2 - 3)
Checking for a perfect cube :
9.2 v4 - 5v3 + 6v2 - 3 is not a perfect cube
Trying to factor by pulling out :
9.3 Factoring: v4 - 5v3 + 6v2 - 3
Thoughtfully split the expression at hand into groups, each group having two terms :
Group 1: 6v2 - 3
Group 2: v4 - 5v3
Pull out from each group separately :
Group 1: (2v2 - 1) • (3)
Group 2: (v - 5) • (v3)
Bad news !! Factoring by pulling out fails :
The groups have no common factor and can not be added up to form a multiplication.
Polynomial Roots Calculator :
9.4 Find roots (zeroes) of : F(v) = v4 - 5v3 + 6v2 - 3
See theory in step 6.2
In this case, the Leading Coefficient is 1 and the Trailing Constant is -3.
The factor(s) are:
of the Leading Coefficient : 1
of the Trailing Constant : 1 ,3
Let us test ....
| P | Q | P/Q | F(P/Q) | Divisor | |||||
|---|---|---|---|---|---|---|---|---|---|
| -1 | 1 | -1.00 | 9.00 | ||||||
| -3 | 1 | -3.00 | 267.00 | ||||||
| 1 | 1 | 1.00 | -1.00 | ||||||
| 3 | 1 | 3.00 | -3.00 |
Polynomial Roots Calculator found no rational roots
Final result :
3 • (v4 5v3 + 6v2 - 3)
————————————————————————
v2
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