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
Artemon [7]
3 years ago
9

2cos^2x+cosx-1=0 Find the degree solutions

Mathematics
1 answer:
Lapatulllka [165]3 years ago
4 0
2cos²x+cos x-1=0

cos x=t

2t²+t-1=0

t=[-1⁺₋√(-1+8)]/2=(-1⁺₋3)/4
We have two possible set solutions:
First set solutions.
t₁=(-1-3)/2=-4/4=-1   
cos x=-1  ⇒x=cos⁻¹ (-1)=π +2kπ    or     180º+360ºk    (k=(...-2,-1,0,1,2...)

Second set solutions:
t₂=(-1+3)/4=2/4=1/2

cos x=1/2  ⇒ x=cos⁻¹ 1/2=π/3+2kπ   U   5π/3+ 2kπ   or
60º+360ºK  U 300º+360ºK        (k=...-2,-1,0,1,2,...)

solutions: first set solutions U second set solutions:

Answer in radians : π +2kπ U π/3+2kπ U 5π/3+ 2kπ   (k=...-1,0,1,...)
Answer is degrees: 180º+360ºk U 60º+360ºK  U 300º+360ºK        (k=...-2,-1,0,1,2,...)
You might be interested in
Que es el volumen (en matematicas)
Elan Coil [88]

Answer:

En matemáticas, el volumen se puede definir como el espacio tridimensional encerrado por un límite u ocupado por un objeto. Aquí, los bloques y los libros ocupan espacio. ... El volumen de un objeto se mide en unidades cúbicas como centímetros cúbicos, pulgada cúbica, pie cúbico, metro cúbico.

Step-by-step explanation:

espero que esto ayude.

7 0
2 years ago
What is the recursive rule for the following sequence: -9, -2, 5, 12, ….
tino4ka555 [31]

Answer:

The answer is option (C)=an-1+7

Step-by-step explanation:

A recursive rule is a formula that in which each term is expressed as a function of its preceding term(s), meaning in order to get to the nth term you have to express it in a form of the term that comes before it. In our case the a(n-1) term

So for the sequence -9, -2, 5, 12

The nth term is any number on the sequence and

  • -2 is the a(n-1) term for -9
  • 5 is the a(n-1) term for -2
  • 12 is the a(n-1) term for 5

So we need to find out what we have to do to the preceding term to get the next.

To get -2 from -9 we have to add 7 to -9; -9+7=-2

To get 5 from -2 we have to add 7 to -2; -2+7=5

To get 12 from 5 we add 7 to 5; 7+5=12

So the recursive rule would be= a n-1+7

5 0
3 years ago
Whats the are of a parralelagram thats 9,3,20 23 5
vampirchik [111]

Answer:

Step-by-step explanation:

That is not a parallelogram. It has more than four sides.

Area of the white part of the figure is 4×20 = 80 m²

If you expand the figure to include the white part, its area is 9×23 = 207 m².

Green area = 207-80 = 127 m²

8 0
2 years ago
22% of the customers visiting the suit department of a certain store will purchase a suit, 30% will purchase a shirt and 28% wil
Ulleksa [173]

Answer:

If there are 1000 customers in the store one week, how many will purchase exactly one of these items

1000 CUSTOMERS*28%=280

Step-by-step explanation:

A The event that a persons buys a suit  

B The event that a person buys a shirt  

C The event that a person buys a tie  

 

P(A)=  22%

P(B)=  30%

P(C)=  28%

P(AB)= 11%

P(AC)= 14%

P(BC)= 10%

P(ABC)= 6%

A u B u C Is the event that any item is bougth

AC u AC u BC Is the event that any two events occured

So the wanted probability is

P[(A u B u C )(AB u AC u BC)^c

P[(A u B u C )=P(AB)+ P(BC)+P(BC)

P[(A u B u C ) =0.22+0.30+0.28-0.11-0.14.-0.10+0.06

                      =0,51

0,51=+0,23+P[(A u B u C )(AB u AC u BC)^c

        =0,28

1000 CUSTOMERS*28%=280

6 0
3 years ago
Bob is asked to construct a probability model for rolling a pair of fair dice. He lists the outcomes as​ 2, 3,​ 4, 5,​ 6, 7,​ 8,
vichka [17]

Answer and Step-by-step explanation:

For 2 dice, we have 36 possibles outcomes:

D₁ = {1,2,3,4,5,6}

D₂ = {1,2,3,4,5,6}

U = ({1,1};{1,2};{1,3};...;{2,1};{2,2};...;{6,6})

This way, it's 6 for D₁ and 6 for D₂, 6.6 = 36

The possible 3 that might appear when rolling a pair of dice would be

{1,2} and {2,1}, so, 2.

The probability of rolling 3 is 2/36 = 1/18

4 0
3 years ago
Other questions:
  • Explain how 9*4 can help you find 9*8.
    10·2 answers
  • How to find the answer ?
    9·1 answer
  • Markus scared 85, 92, 82, and 94 on the first four tests of the semester. His teacher has not yet told him his score on his fift
    13·2 answers
  • A high speed elevator can rise 500 feet in 30 seconds. Which expression represents the rate, in feet per minute, of the elevator
    13·2 answers
  • a sporting goods company can ship 6 footballs in each carton. how many cartons are needed to ship 75 footballs
    12·2 answers
  • A survey asked people whether their pets are picky eaters. For these results, are being a picky eater and being a cat independen
    13·1 answer
  • 7. If the area of a rug is 48 square feet, what are the possible dimensions of the rug? (2 points)
    7·2 answers
  • I hope you guys can see it but if you answer it i’ll make you the brainiest
    9·1 answer
  • Please Answer for brainliy i only have 5 mins left of class
    15·1 answer
  • A bus makes a stop at 2:30, letting off 12 people and letting on 3. The bus makes another stop ten minutes later to let off 2 mo
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!