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
Alenkinab [10]
3 years ago
7

Which are the solutions of the quadratic equation? x2 = –5x – 3

Mathematics
1 answer:
Svetradugi [14.3K]3 years ago
4 0
x^2=-5x-3\\x^2+5x+3=0\\\\a=1;\ b=5;\ c=3\\\Delta=b^2-4ac\\\\\Delta=5^2-4\cdot1\cdot3=25-12=13 \ \textgreater \  0\\\\then\\x_1=\dfrac{-b-\sqer\Delta}{2a}\ and\ x_2=\dfrac{-b+\sqrt\Delta}{2a}\\\\x_1=\dfrac{-5-\sqrt{13}}{2\cdot1}=\boxed{\dfrac{-5-\sqrt{13}}{2}}\\\\x_2=\dfrac{-5+\sqrt{13}}{2\cdot1}=\boxed{\dfrac{-5+\sqrt{13}}{2}}
You might be interested in
On a stopwatch, the tip of the second hand moves 2 cm in 15 seconds. How long is the second hand (to the nearest tenth)?
Komok [63]
The 'seconds' hand on the watch goes all the way around in 1 minute. <span>15 seconds is 1/4 of a complete 1-minute revolution. </span>So, the 2 cm is 1/4 of the way around the circle that the tip makes. This makes the full circumference of the circle 8cm.

<span>The length of the second hand will be the radius of the circle. Use the following equation: </span>

2 pi radius  =  circumference

Since we know the circumference, plug that in, and solve for the radius:

2 pi radius  =  8 cm              
radius  =  8cm / 2 pi  =<span>  1.27 cm</span>
4 0
4 years ago
Read 2 more answers
Factorise:6x^2+7x-2​
Klio2033 [76]
Your anwser is 6x^2+7x-2 :) have a good day
6 0
4 years ago
Do not understand!!!!!
Nadya [2.5K]
The answer to this equation is 2
7 0
3 years ago
Which list of ordered palrs represents solutions to x+y=2?
Aneli [31]
This is simple. Just add the x and y values of each ordered pair to see which ones equals 2.

The answer is (-4, 6), (0, 2), (4, -2)
8 0
4 years ago
Prove cosh 3x = 4 cosh^3 x - 3 cosh x.
Snezhnost [94]
Prove we are to prove  4(coshx)^3 - 3(coshx) we are asked to prove 4(coshx)^3 - 3(coshx) to be equal to cosh 3x
= 4(e^x+e^(-x))^3/8 - 3(e^x+e^(-x))/2 = e^3x /2 +3e^x /2 + 3e^(-x) /2 + e^(-3x) /2 - 3(e^x+e^(-x))/2 = e^(3x) /2 + e^(-3x) /2 = cosh(3x) = LHS Since y = cosh x satisfies the equation if we replace the "2" with cosh3x, we require cosh 3x = 2 for the solution to work. 
i.e. e^(3x)/2 + e^(-3x)/2 = 2 
Setting e^(3x) = u, we have u^2 + 1 - 4u = 0 
u = (4 + sqrt(12)) / 2 = 2 + sqrt(3), so x = ln((2+sqrt(3))/2) /3, Or u = (4 - sqrt(12)) / 2 = 2 - sqrt(3), so x = ln((2-sqrt(3))/2) /3, 
Therefore, y = cosh x = e^(ln((2+sqrt(3))/2) /3) /2 + e^(-ln((2+sqrt(3))/2) /3) /2 = (2+sqrt(3))^(1/3) / 2 + (-2-sqrt(3))^(1/3) to be equ
= 4(e^x+e^(-x))^3/8 - 3(e^x+e^(-x))/2 
= e^3x /2 +3e^x /2 + 3e^(-x) /2 + e^(-3x) /2 - 3(e^x+e^(-x))/2 
= e^(3x) /2 + e^(-3x) /2 
= cosh(3x) 
= LHS 

<span>Therefore, because y = cosh x satisfies the equation IF we replace the "2" with cosh3x, we require cosh 3x = 2 for the solution to work. </span>

i.e. e^(3x)/2 + e^(-3x)/2 = 2 

Setting e^(3x) = u, we have u^2 + 1 - 4u = 0 

u = (4 + sqrt(12)) / 2 = 2 + sqrt(3), so x = ln((2+sqrt(3))/2) /3, 
Or u = (4 - sqrt(12)) / 2 = 2 - sqrt(3), so x = ln((2-sqrt(3))/2) /3, 

Therefore, y = cosh x = e^(ln((2+sqrt(3))/2) /3) /2 + e^(-ln((2+sqrt(3))/2) /3) /2 
= (2+sqrt(3))^(1/3) / 2 + (-2-sqrt(3))^(1/3)
3 0
4 years ago
Other questions:
  • If it is geometric sequence, choose the common ratio 21,42,126,504
    8·1 answer
  • Each year the Miller county country club sponsors a tennis tournament. Play starts with 128 participants. During each round, hal
    11·1 answer
  • An office manager estimates that she spends 40% of her 30-minute lunch
    6·1 answer
  • Please help! forgot how to subtract integers!
    6·1 answer
  • A water tank already contains 55 gallons of water when Baxter begins to fill it. Water flows into the tank at a rate of 8 gallon
    7·1 answer
  • It’s due tonight I would appreciate the help
    13·2 answers
  • A 6 pack of batteries cost $7.80. How much is 1 battery?​
    12·2 answers
  • Which is considered a rational number?
    7·1 answer
  • The difference of twice a number and 9.
    8·2 answers
  • A= 1 2 3 4 5 is the solution of a set of the variable equation<br> 3x=15
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!