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
kenny6666 [7]
3 years ago
9

Finding the roots by completing the square

Mathematics
1 answer:
Andrej [43]3 years ago
6 0
For y=x^2-6x-11

complete the square

so roots
set y=0
0=x^2-6x-11

group x terms
0=(x^2-6x)-11
take 1/2 of linear coefient (-6) and square it
-6/2=-3, (-3)^2=9
add positive and neative to inside of parenthasees
0=(x^2-6x+9-9)-11
complete square
0=((x-3)^2-9)-11
expand
0=(x-3)^2-9-11
0=(x-3)^2-20
add 20 to both sides
20=(x-3)^2
sqrt both sides
remember positive and negative roots

+/-2√5=x-3
add 3 to both sides
3+/-2√5=x

so
x=3+2√5 and 3-2√5
You might be interested in
Why did this app make me fail my test?
Yuki888 [10]
Probably because people gave you the wrong answer. Not saying they did this intentionally....
4 0
3 years ago
Read 2 more answers
Which number is a rational number?
nasty-shy [4]

Answer:

B. 2.6457513110...

and

C. 17.156

Step-by-step explanation:

A rational number is an integer, fraction, terminating decimal, or repeating decimal.

hope this helps!

brainliest appreciated:)

7 0
2 years ago
Read 2 more answers
The answer to this question
In-s [12.5K]

Answer: There is no quetion this is not helpful i can't help if i don't no the problem

Step-by-step explanation:

8 0
3 years ago
The ages of the winners of a cycling tournament are approximately bell-shaped. The mean age is 27.2 years, with a standard devia
elena-14-01-66 [18.8K]

Answer:

a. z-score = -1.2

b. The age 23 years old is -1.2 standard deviations below the mean

c. The age is not unusual

Step-by-step explanation:

a. Transformation to z-score

Mathematically;

z-score = (x - μ)/σ

where σ and μ are the standard deviation and the mean respectively.

From the question, x = 23, μ = 27.2 and σ = 3.5

Let’s put these into the equation;

z-score = (23-27.2)/3.5 = -1.2

b. Interpretation of result

The interpretation is that 23 years old is -1.2 standard deviations below the mean

c. Determination

The age is not unusual. This is because any z-value below -2 or above 2 is considered unusual

-1.2 is above -2 and thus it is not unusual

7 0
2 years ago
One circular table has a diameter of 9 ft, and another circular table has a diameter of 20 ft. How much greater is the area of t
morpeh [17]
Smaller circle:
diameter = 9 ft
radius = diameter/2 = (9 ft)/2 = 4.5 ft
A = pi(r^2) = 3.14159 * (4.5 ft)^2 = 63.62 ft^2

Larger circle:
diameter = 20 ft
radius = diameter/2 = (20 ft)/2 = 10 ft
A = pi(r^2) = 3.14159 * (10 ft)^2 = 314.159 ft^2

Difference = larger are - smaller area

Difference = 314.16 ft^2 - 63.62 ft^2 = 250.54 ft^2

Answer: About 251 ft^2
5 0
3 years ago
Other questions:
  • What is an dividend in a math equation?
    6·1 answer
  • A store is having a sale on jellybeans and almonds. for 5 pounds of jellybeans and 3 pounds of almonds, the total cost is $22. F
    9·1 answer
  • Find the markup and the cost of the following item. Round answers to the nearest cent.
    9·1 answer
  • anayas team won 5 out of every 7 games this season if the team played 28 games this season how many games did they win
    6·1 answer
  • In the straightedge and compass construction of the equilateral triangle below, which o the following reasons can you use to pro
    10·2 answers
  • Number of acute, obtuse and right angles inside each shape
    11·2 answers
  • What is 5/8 times 5/6
    5·2 answers
  • What is the solution to the division problem below? (You can use long division or synthetic division) X^3 + x^2 - 11x + 4/x + 4
    12·2 answers
  • What is two ratios equivalent to 3:11​
    5·2 answers
  • I need help please!!!<br><br>Thank you so much! :)​
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!