Solution - Finding the roots of polynomials
Other Ways to Solve
Finding the roots of polynomialsStep by Step Solution
Step 1 :
Equation at the end of step 1 :
Step 2 :
x3 - 4x2 + 3
Simplify ————————————
x
Polynomial Roots Calculator :
2.1 Find roots (zeroes) of : F(x) = x3 - 4x2 + 3
Polynomial Roots Calculator is a set of methods aimed at finding values of x for which F(x)=0
Rational Roots Test is one of the above mentioned tools. It would only find Rational Roots that is numbers x 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 | -2.00 | ||||||
-3 | 1 | -3.00 | -60.00 | ||||||
1 | 1 | 1.00 | 0.00 | x - 1 | |||||
3 | 1 | 3.00 | -6.00 |
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
x3 - 4x2 + 3
can be divided with x - 1
Polynomial Long Division :
2.2 Polynomial Long Division
Dividing : x3 - 4x2 + 3
("Dividend")
By : x - 1 ("Divisor")
dividend | x3 | - | 4x2 | + | 3 | ||||
- divisor | * x2 | x3 | - | x2 | |||||
remainder | - | 3x2 | + | 3 | |||||
- divisor | * -3x1 | - | 3x2 | + | 3x | ||||
remainder | - | 3x | + | 3 | |||||
- divisor | * -3x0 | - | 3x | + | 3 | ||||
remainder | 0 |
Quotient : x2-3x-3 Remainder: 0
Trying to factor by splitting the middle term
2.3 Factoring x2-3x-3
The first term is, x2 its coefficient is 1 .
The middle term is, -3x its coefficient is -3 .
The last term, "the constant", is -3
Step-1 : Multiply the coefficient of the first term by the constant 1 • -3 = -3
Step-2 : Find two factors of -3 whose sum equals the coefficient of the middle term, which is -3 .
-3 | + | 1 | = | -2 | ||
-1 | + | 3 | = | 2 |
Observation : No two such factors can be found !!
Conclusion : Trinomial can not be factored
Polynomial Long Division :
2.4 Polynomial Long Division
Dividing : x2-3x-3
("Dividend")
By : x ("Divisor")
dividend | x2 | - | 3x | - | 3 | ||
- divisor | * x1 | x2 | |||||
remainder | - | 3x | - | 3 | |||
- divisor | * -3x0 | - | 3x | ||||
remainder | - | 3 |
Quotient : x-3
Remainder : -3
Final result :
(x2 - 3x - 3) • (x - 1)
———————————————————————
x
See results of polynomial long division:
1. In step #02.04
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