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
4, 6, 2, 6, 9, 3, 5<br> Mode ?? <br> Median ?? Mean??
sergeinik [125]
Mean: 5
Mode: 6
Median : 5
8 0
3 years ago
Read 2 more answers
One eighth of Tony's books are mystery books He has 3 Mystery books how many books does Tony have in all
kolezko [41]
The answer to <span>One eighth of Tony's books are mystery books He has 3 Mystery books how many books does Tony have in all is 24

</span>
5 0
3 years ago
Read 2 more answers
A cell phone can receive 120 messages per minute. At this rate, how
GrogVix [38]


First, find out how many messages are received a second. Do this by dividing messages by 60 seconds.

120/60 = 2 messages a second

now multiply 2 by 150

2*150 = 300messages in 150 seconds

your answer is (3) 300

5 0
4 years ago
Help me pls due in 5 mins​
Drupady [299]

Answer: 215\ cm^2

Step-by-step explanation:

Given

Here the given figure can be divided into two shapes i.e. rectangle and a trapezium

For rectangle ABCD Area = 10\times8=80\ cm^2

Area of trapezium CEFD Area is \frac{1}{2}[\text{sum of non-parallel sides}]\times[\text{distance between them}]

\Rightarrow \frac{1}{2}\times [10+17][10]=135\ cm^2

Total shaded area =80+135=215\ cm^2

5 0
3 years ago
Enter the equation of the line in the form y=mx+b where m is the slope and b is the y-intercept.
Gelneren [198K]

Answer:

y=3/1+-2

Step-by-step explanation:

7 0
3 years ago
Read 2 more answers
Other questions:
  • Solve the compound inequality 6b &lt; 42 or 4b + 12 &gt; 8. (1 point)
    15·1 answer
  • Carys calculates the total amount EEE, in dollars, that she earns for working hhh hours using the equation E=10hE=10hE, equals,
    11·2 answers
  • Tomas created a function table using the equation y = x + 4. Which table is correct?
    8·1 answer
  • A bicycle trail in the shape of a circle has a diameter of 3 miles. Michelle biked around the trail 4 times. About how far did M
    9·1 answer
  • Find x and y of this shape.
    5·1 answer
  • Elizabeth wants to use a standard number cube to do a simulation for a scenario that
    10·1 answer
  • THIS IS EASY!! PLS HELP ME! ASAP PLS
    7·2 answers
  • $100,00 discount 21%
    11·2 answers
  • How many solutions does the system have?
    11·1 answer
  • Find the indefinite integral
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!