Solve Polynomialrootcalculator X^3-4x^2-3x-10=0 Tiger Algebra ...

Step by step solution :

Step 1 :

Equation at the end of step 1 :

(((x3) - 22x2) - 3x) - 10 = 0

Step 2 :

Checking for a perfect cube :

2.1 x3-4x2-3x-10 is not a perfect cube

Trying to factor by pulling out :

2.2 Factoring: x3-4x2-3x-10 Thoughtfully split the expression at hand into groups, each group having two terms :Group 1: -3x-10 Group 2: x3-4x2 Pull out from each group separately :Group 1: (3x+10) • (-1)Group 2: (x-4) • (x2)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 :

2.3 Find roots (zeroes) of : F(x) = x3-4x2-3x-10Polynomial 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 integersThe 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 CoefficientIn this case, the Leading Coefficient is 1 and the Trailing Constant is -10. The factor(s) are: of the Leading Coefficient : 1 of the Trailing Constant : 1 ,2 ,5 ,10 Let us test ....

PQP/QF(P/Q)Divisor
-1 1 -1.00 -12.00
-2 1 -2.00 -28.00
-5 1 -5.00 -220.00
-10 1 -10.00 -1380.00
1 1 1.00 -16.00
2 1 2.00 -24.00
5 1 5.00 0.00 x-5
10 1 10.00 560.00

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 x3-4x2-3x-10 can be divided with x-5

Polynomial Long Division :

2.4 Polynomial Long Division Dividing : x3-4x2-3x-10 ("Dividend") By : x-5 ("Divisor")

dividend x3 - 4x2 - 3x - 10
- divisor * x2 x3 - 5x2
remainder x2 - 3x - 10
- divisor * x1 x2 - 5x
remainder 2x - 10
- divisor * 2x0 2x - 10
remainder0

Quotient : x2+x+2 Remainder: 0

Trying to factor by splitting the middle term

2.5 Factoring x2+x+2 The first term is, x2 its coefficient is 1 .The middle term is, +x its coefficient is 1 .The last term, "the constant", is +2 Step-1 : Multiply the coefficient of the first term by the constant 12 = 2 Step-2 : Find two factors of 2 whose sum equals the coefficient of the middle term, which is 1 .

-2 + -1 = -3
-1 + -2 = -3
1 + 2 = 3
2 + 1 = 3

Observation : No two such factors can be found !! Conclusion : Trinomial can not be factored

Equation at the end of step 2 :

(x2 + x + 2) • (x - 5) = 0

Step 3 :

Theory - Roots of a product :

3.1 A product of several terms equals zero.When a product of two or more terms equals zero, then at least one of the terms must be zero.We shall now solve each term = 0 separatelyIn other words, we are going to solve as many equations as there are terms in the productAny solution of term = 0 solves product = 0 as well.

Parabola, Finding the Vertex :

3.2 Find the Vertex of y = x2+x+2Parabolas have a highest or a lowest point called the Vertex . Our parabola opens up and accordingly has a lowest point (AKA absolute minimum) . We know this even before plotting "y" because the coefficient of the first term, 1 , is positive (greater than zero).Each parabola has a vertical line of symmetry that passes through its vertex. Because of this symmetry, the line of symmetry would, for example, pass through the midpoint of the two x -intercepts (roots or solutions) of the parabola. That is, if the parabola has indeed two real solutions.Parabolas can model many real life situations, such as the height above ground, of an object thrown upward, after some period of time. The vertex of the parabola can provide us with information, such as the maximum height that object, thrown upwards, can reach. For this reason we want to be able to find the coordinates of the vertex.For any parabola,Ax2+Bx+C,the x -coordinate of the vertex is given by -B/(2A) . In our case the x coordinate is -0.5000 Plugging into the parabola formula -0.5000 for x we can calculate the y -coordinate : y = 1.0 * -0.50 * -0.50 + 1.0 * -0.50 + 2.0 or y = 1.750

Parabola, Graphing Vertex and X-Intercepts :

Root plot for : y = x2+x+2 Axis of Symmetry (dashed) {x}={-0.50} Vertex at {x,y} = {-0.50, 1.75} Function has no real roots

Solve Quadratic Equation by Completing The Square

3.3 Solving x2+x+2 = 0 by Completing The Square . Subtract 2 from both side of the equation : x2+x = -2Now the clever bit: Take the coefficient of x , which is 1 , divide by two, giving 1/2 , and finally square it giving 1/4 Add 1/4 to both sides of the equation : On the right hand side we have : -2 + 1/4 or, (-2/1)+(1/4) The common denominator of the two fractions is 4 Adding (-8/4)+(1/4) gives -7/4 So adding to both sides we finally get : x2+x+(1/4) = -7/4Adding 1/4 has completed the left hand side into a perfect square : x2+x+(1/4) = (x+(1/2)) (x+(1/2)) = (x+(1/2))2 Things which are equal to the same thing are also equal to one another. Since x2+x+(1/4) = -7/4 and x2+x+(1/4) = (x+(1/2))2 then, according to the law of transitivity, (x+(1/2))2 = -7/4We'll refer to this Equation as Eq. #3.3.1 The Square Root Principle says that When two things are equal, their square roots are equal.Note that the square root of (x+(1/2))2 is (x+(1/2))2/2 = (x+(1/2))1 = x+(1/2)Now, applying the Square Root Principle to Eq. #3.3.1 we get: x+(1/2) = -7/4 Subtract 1/2 from both sides to obtain: x = -1/2 + √ -7/4 In Math, i is called the imaginary unit. It satisfies i2 =-1. Both i and -i are the square roots of -1 Since a square root has two values, one positive and the other negative x2 + x + 2 = 0 has two solutions: x = -1/2 + √ 7/4 i or x = -1/2 - √ 7/4 i Note that 7/4 can be written as 7 / √ 4 which is 7 / 2

Solve Quadratic Equation using the Quadratic Formula

3.4 Solving x2+x+2 = 0 by the Quadratic Formula . According to the Quadratic Formula, x , the solution for Ax2+Bx+C = 0 , where A, B and C are numbers, often called coefficients, is given by : - B ± √ B2-4AC x = ———————— 2A In our case, A = 1 B = 1 C = 2 Accordingly, B2 - 4AC = 1 - 8 = -7Applying the quadratic formula : -1 ± √ -7 x = ————— 2In the set of real numbers, negative numbers do not have square roots. A new set of numbers, called complex, was invented so that negative numbers would have a square root. These numbers are written (a+b*i) Both i and -i are the square roots of minus 1Accordingly, -7 = √ 7 • (-1) = √ 7 • √ -1 = ± √ 7 i 7 , rounded to 4 decimal digits, is 2.6458 So now we are looking at: x = ( -1 ± 2.646 i ) / 2Two imaginary solutions :

x =(-1+√-7)/2=(-1+i 7 )/2= -0.5000+1.3229i or: x =(-1-√-7)/2=(-1-i 7 )/2= -0.5000-1.3229i

Solving a Single Variable Equation :

3.5 Solve : x-5 = 0Add 5 to both sides of the equation : x = 5

Three solutions were found :

  1. x = 5
  2. x =(-1-√-7)/2=(-1-i 7 )/2= -0.5000-1.3229i
  3. x =(-1+√-7)/2=(-1+i 7 )/2= -0.5000+1.3229i

Từ khóa » F(x)=x^3+4x^2-3x+10 G(x)=x+4