Math, asked by sdft988, 1 year ago

x^4+14x^4+48
can I get the answer

Answers

Answered by ankitrishab
0
     Factoring  x4-14x2+48 

The first term is,  x4  its coefficient is  1 .
The middle term is,  -14x2  its coefficient is  -14 .
The last term, "the constant", is  +48 

Step-1 : Multiply the coefficient of the first term by the constant   1 • 48 = 48 

Step-2 : Find two factors of  48  whose sum equals the coefficient of the middle term, which is   -14 .

     -48   +   -1   =   -49     -24   +   -2   =   -26     -16   +   -3   =   -19     -12   +   -4   =   -16     -8   +   -6   =   -14   That's it


Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above,  -8  and  -6 
                     x4 - 8x2 - 6x2 - 48

Step-4 : Add up the first 2 terms, pulling out like factors :
                    x2 • (x2-8)
              Add up the last 2 terms, pulling out common factors :
                    6 • (x2-8)
Step-5 : Add up the four terms of step 4 :
                    (x2-6)  •  (x2-8)
             Which is the desired factorization

Trying to factor as a Difference of Squares :

 2.2      Factoring:  x2-6 

Theory : A difference of two perfect squares,  A2 - B2  can be factored into  (A+B) • (A-B)

Proof :  (A+B) • (A-B) =
         A2 - AB + BA - B2 =
         A2 - AB + AB - B2 = 
         A2 - B2

Note :  AB = BA is the commutative property of multiplication. 

Note :  - AB + AB equals zero and is therefore eliminated from the expression.

Check : 6 is not a square !! 

Ruling : Binomial can not be factored as the difference of two perfect squares.

Trying to factor as a Difference of Squares :

 2.3      Factoring:  x2-8 

Check : 8 is not a square !! 

Ruling : Binomial can not be factored as the difference of two perfect squares.

Equation at the end of step  2  :

(x2 - 6) • (x2 - 8) = 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 separately 

 In other words, we are going to solve as many equations as there are terms in the product 

 Any solution of term = 0 solves product = 0 as well.

Solving a Single Variable Equation :

 3.2      Solve  :    x2-6 = 0 

 Add  6  to both sides of the equation : 
                      x2 = 6 
 
 When two things are equal, their square roots are equal. Taking the square root of the two sides of the equation we get:  
                      x  =  ± √ 6  

 The equation has two real solutions  
 These solutions are  x = ± √6 = ± 2.4495  
 

Solving a Single Variable Equation :

 3.3      Solve  :    x2-8 = 0 

 Add  8  to both sides of the equation : 
                      x2 = 8 
 
 When two things are equal, their square roots are equal. Taking the square root of the two sides of the equation we get:  
                      x  =  ± √ 8  

 Can  √ 8 be simplified ?

Yes!   The prime factorization of  8   is
   2•2•2  
To be able to remove something from under the radical, there have to be  2  instances of it (because we are taking a square i.e. second root).

√ 8   =  √ 2•2•2   =
                ±  2 • √ 2 

The equation has two real solutions  
 These solutions are  x = 2 • ± √2 = ± 2.8284  
 

Supplement : Solving Quadratic Equation Directly

Solving  x4-14x2+48  = 0 directly

Earlier we factored this polynomial by splitting the middle term. let us now solve the equation by Completing The Square and by using the Quadratic Formula

Solving a Single Variable Equation :

Equations which are reducible to quadratic :

 4.1     Solve   x4-14x2+48 = 0

This equation is reducible to quadratic. What this means is that using a new variable, we can rewrite this equation as a quadratic equation Using  w , such that  w = x2  transforms the equation into :
 w2-14w+48 = 0

Solving this new equation using the quadratic formula we get two real solutions :
   8.0000  or   6.0000

Now that we know the value(s) of  w , we can calculate  x  since  x  is  √ w  

Doing just this we discover that the solutions of 
   x4-14x2+48 = 0
  are either : 
  x =√ 8.000 = 2.82843  or :
  x =√ 8.000 = -2.82843  or :
  x =√ 6.000 = 2.44949  or :
  x =√ 6.000 = -2.44949 

Four solutions were found :

 x = 2 • ± √2 = ± 2.8284

 x = ± √6 = ± 2.4495

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