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jenyasd209 [6]
3 years ago
12

Find all values of x in the interval [0, 2π] that satisfy the equation. (Enter your answers as a comma-separated list.) 18 + 9 c

os(2x) = 27 cos(x)
Mathematics
1 answer:
Gekata [30.6K]3 years ago
4 0
Using the identity cos(2x) = 2 cos^2x - 1
18 + 9(2 cos^2 x - 1) = 27 cos x
18cos^2 x - 27 cos x + 9 = 0
2 cos^ x - 3 cos x + 1 = 0

(2 cos x  - 1 )(cos x  - 1 ) = 0

cos x = 1/2 , 1 

x =  pi/3, 5pi/3, 0, 2pi     answer
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A kite is designed on a rectangular grid with squares that measure 1cm by 1 cm. A hexagonal piece within the kite will be reserv
Nata [24]

Answer:

The answer is the first answer

P = 8 + 4√13 cm

A = 36 cm²

Step-by-step explanation:

* Lets study the figure

- Its a kite with two diagonals

- The shortest one is 12 cm

- The longest one is 26 ⇒ axis of symmetry of the kite

- the shortest diagonal divides the longest into two parts

- The smallest part is 8 cm and the largest one is 18 cm

* To find the area reserved for the logo divide

 the hexagonal piece into two congruent trapezium

- The length of the two parallel bases are 4 cm and 8 cm and

  its height is 3 cm

- The length of non-parallel bases can calculated by Pythagoras rule

∵ The lengths of the two perpendicular sides are 2 cm and 3 cm

- 3 cm is the height of the trapezium

- 2 cm its the difference between the 2 parallel bases ÷ 2

  (8 - 4)/2 = 4/2 = 2 cm

∴ The length of the non-parallel base = √(2² + 3²) = √13

* Now we can find the area of the space reserved for the logo

- The area of the trapezium = (1/2)(b1 + b2) × h

∴ The area = (1/2)(4 + 8) × 3 = (1/2)(12)(3) = 18 cm²

∵ The space reserved for the logo are 2 trapezium

∴ The area reserved for the logo = 2 × 18 = 36 cm²

* The area of the reserved space for the logo = 36 cm²

* The perimeter of the reserved space for the logo is the

  perimeter of the hexagon

∵ The lengths of the sides of the hexagon are:

   4 cm , 4 cm , √13 cm , √13 cm , √13 cm , √13 cm

∴ The perimeter = 2(4) + 4(√13) = 8 + 4√13 cm

* The perimeter of the reserved space for the logo = 8 + 4√13 cm

4 0
3 years ago
An industrial psychologist consulting with Lara music stores knows that the average number of complaints management receives eac
xeze [42]

Answer:

Step-by-step explanation:

H0 : μ ≥ 6

H1 : μ < 6

Test statistic :

n = 20

Sample Mean, x = 3

σ = 1.5

Test statistic = (x - μ) ÷ σ/sqrt(n)

Test statistic = (3 - 6) ÷ 1.5/sqrt(20)

Test statistic = - 3 / 0.3354101

Test statistic = −8.944271

Since, sample size is < 30 ;

Obtaining the Critical value using the from T;

Tcritical at 0.05, df = 19 = - 1.729

Tstatistic < Tcritical

−8.944271 < - 1.729

Hence, we reject the Null:

We can conclude that there is significant evidence that the number of complaints received by Lara music store is different from number of complaints received by music stores in general.

3 0
3 years ago
What is 42 to the power of 9 divided by 2.and Multipied by 6?
bekas [8.4K]
Exact form:
1220014151548416

Decimal form:
1.22001415*10^15
5 0
4 years ago
Read 2 more answers
How many fluid ounces are in 3 1/4 cups?
Andre45 [30]

Answer: The Answer is 26

Step-by-step explanation: Well, I first divided 3 by 4 and then I got 1 and then I did 1 + 23 and got 24 and then 3 made even is 2 so I added 2 and got 26!

7 0
2 years ago
Read 2 more answers
Find the perimeter and area of the figure. Round to the nearest tenth if necessary.
Stella [2.4K]

Answer: D

Step-by-step explanation:

A=\frac{1}{2}bh\\\\A=\frac{1}{2}(4.8)(7.2)\\\\A \approx \boxed{17.3}

3 0
2 years ago
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