1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Brut [27]
4 years ago
15

What is the solution of the equation x2 – 2x = -2?

Mathematics
1 answer:
professor190 [17]4 years ago
7 0

Answer:

Two solutions were found :

x =(2-√-4)/2=1-i= 1.0000-1.0000i

x =(2+√-4)/2=1+i= 1.0000+1.0000i

Step-by-step explanation:

Trying to factor by splitting the middle term

1.1     Factoring  x2-2x+2

The first term is,  x2  its coefficient is  1 .

The middle term is,  -2x  its coefficient is  -2 .

The last term, "the constant", is  +2

Step-1 : Multiply the coefficient of the first term by the constant   1 • 2 = 2

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

     -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  1  :

 x2 - 2x + 2  = 0

Step  2  :

Parabola, Finding the Vertex :

2.1      Find the Vertex of   y = x2-2x+2

Parabolas 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   1.0000  

Plugging into the parabola formula   1.0000  for  x  we can calculate the  y -coordinate :

 y = 1.0 * 1.00 * 1.00 - 2.0 * 1.00 + 2.0

or   y = 1.000

Parabola, Graphing Vertex and X-Intercepts :

Root plot for :  y = x2-2x+2

Axis of Symmetry (dashed)  {x}={ 1.00}

Vertex at  {x,y} = { 1.00, 1.00}

Function has no real roots

Solve Quadratic Equation by Completing The Square

2.2     Solving   x2-2x+2 = 0 by Completing The Square .

Subtract  2  from both side of the equation :

  x2-2x = -2

Now the clever bit: Take the coefficient of  x , which is  2 , divide by two, giving  1 , and finally square it giving  1

Add  1  to both sides of the equation :

 On the right hand side we have :

  -2  +  1    or,  (-2/1)+(1/1)

 The common denominator of the two fractions is  1   Adding  (-2/1)+(1/1)  gives  -1/1

 So adding to both sides we finally get :

  x2-2x+1 = -1

Adding  1  has completed the left hand side into a perfect square :

  x2-2x+1  =

  (x-1) • (x-1)  =

 (x-1)2

Things which are equal to the same thing are also equal to one another. Since

  x2-2x+1 = -1 and

  x2-2x+1 = (x-1)2

then, according to the law of transitivity,

  (x-1)2 = -1

We'll refer to this Equation as  Eq. #2.2.1  

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   is

  (x-1)2/2 =

 (x-1)1 =

  x-1

Now, applying the Square Root Principle to  Eq. #2.2.1  we get:

  x-1 = √ -1

Add  1  to both sides to obtain:

  x = 1 + √ -1

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 - 2x + 2 = 0

  has two solutions:

 x = 1 + √ 1 •  i

  or

 x = 1 - √ 1 •  i

Solve Quadratic Equation using the Quadratic Formula

2.3     Solving    x2-2x+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   =    -2

                     C   =   2

Accordingly,  B2  -  4AC   =

                    4 - 8 =

                    -4

Applying the quadratic formula :

              2 ± √ -4

  x  =    —————

                   2

In 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 1

Accordingly,√ -4  =

                   √ 4 • (-1)  =

                   √ 4  • √ -1   =

                   ±  √ 4  • i

Can  √ 4 be simplified ?

Yes!   The prime factorization of  4   is

  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).

√ 4   =  √ 2•2   =

               ±  2 • √ 1   =

               ±  2

So now we are looking at:

          x  =  ( 2 ± 2i ) / 2

Two imaginary solutions :

x =(2+√-4)/2=1+i= 1.0000+1.0000i

 or:

x =(2-√-4)/2=1-i= 1.0000-1.0000i

Two solutions were found :

x =(2-√-4)/2=1-i= 1.0000-1.0000i

x =(2+√-4)/2=1+i= 1.0000+1.0000i

Processing ends successfully

You might be interested in
The National Weather Service keeps track of the temperature for a given day in a given city. It also keeps track of this informa
astra-53 [7]
Between 2pm and 4pm the average rate of change is zero.
I can't see the answer choices for the second part of the question.
5 0
3 years ago
Use a net to find the surface area of the right triangular prism shown:
erma4kov [3.2K]

Answer:

256 ft²

Step-by-step explanation:

Net comprises: 2 equal triangles, 2 equal rectangles and 1 smaller rectangle

Area of a triangle = 1/2 x base x height

⇒ area of one triangle = 1/2 x 10 x 7 = 35 ft²

Area of a rectangle = width x length

⇒ area of larger rectangle = 6 x 12 = 72 ft²

⇒ area of smaller rectangle area = 6 x 7 = 42 ft²

⇒ Total area = (2 x 35) + (2 x 72) + 42 = 256 ft²

3 0
2 years ago
You must include an explanation accompanied with your solution. Answers without
nekit [7.7K]

Answer:

B)  $7.50

Step-by-step explanation:

Interest (I) = Principal (P) x Interest Rate (r) x Time (t, in years)

I = 125(.03)(2)

I = 7.5

4 0
3 years ago
HELP :(
puteri [66]
Someone is answering the question.
3 0
3 years ago
Can someone help me pls
marysya [2.9K]

Answer its a

Step-by-step explanation:

7 0
3 years ago
Other questions:
  • In the number 432.901, what digit in the tens place
    8·2 answers
  • I need help on now!!What is one difference??
    8·2 answers
  • Square root of 324x^4
    12·1 answer
  • Which of these represent a function
    5·1 answer
  • Write as a polynomial (3p–1)(2p+5)–6p(p–2)
    9·1 answer
  • a map has a scale of 3cm : 18 km. If riverside & Smithville are 54 km apart they are how far apart on the map?
    13·1 answer
  • Helpppppppppppppppppppppp
    6·1 answer
  • Find the volume and round to the nearest hundredths place when necessary.
    10·1 answer
  • 16. What happens to the equation when y = x becomes y = x + 3? 915<br> 291051 wood to
    11·1 answer
  • Subtracting Fractions with Unlike Denominators
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!