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3 years ago

If sin(a) = cos(2a), then what is the value of a?

Mathematics

1 answer:

Mariulka [41]3 years ago

3 0

Answer:

-90 , 30

Step-by-step explanation:

sina = cos(2a)

= 1 - 2(sina)^2

2(sina)^2 + sina -- 1 = 0

( sina + 1 )( 2sina - 1 ) = 0

sina = -1 or sina = 1/2

=> a = -90 degrees or => a = 30 degrees

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Genie is making cookies and brownies. Each cookie uses 8 grams of flour and each brownie uses 12 grams of flour. She wants to ma

Nikolay [14]

The system of inequalities models correctly the number of cookies is c + b ≥ 125 and 8c + 12b ≤ 2000

Let c represent the number of cookies and let b represent the number of brownies.

Since Genie want to make more than 125 cookies and brownies altogether, hence this is given by:

c + b ≥ 125 (1)

Also, Genie has a total of 2,000 grams of flour, hence:

8c + 12b ≤ 2000 (2)

Therefore the system of inequalities models correctly the number of cookies is c + b ≥ 125 and 8c + 12b ≤ 2000

Find out more at: brainly.com/question/15137133?referrer=searchResults

8 0

3 years ago

2. Find the missing angle x.<br> 155°<br> 60°<br> X

Kryger [21]

Answer:

exterior angle property use ...

the exterior angle of an angle is equal to sum of rest 2 interior angles in a triangle

155 = 60 + x

x = 155 - 60 = 95

8 0

3 years ago

1.12- 2 3/5 QUICK!!!

Rzqust [24]

Answer:

47/5 or 9 2/5

Step-by-step explanation:

12/1-13/5

60-13/5

=47/5

7 0

3 years ago

Read 2 more answers

For a group of 100 people, compute(a) the expected number of days of the year that are birthdays of exactly 3 people.(b) the exp

Scilla [17]

Answer:

Step-by-step explanation:

Leaving leap years, a year contains 365 days.

For a group of 100 people, each person is independent of the other and probability of any day being his birthday has a chance of

$\frac{1}{365}$

a) Probability that exactly 3 people have same birthday = $\frac{1}{365^3}$

Each day is independent of the other

And hence no of days having exactly 3 persons birthday out of 100 persons is binomial with n = 365 and p = $\frac{1}{365^3}$

Expected value of days = np = $\frac{1}{365^2}$

b) Distinct birthdays is binomail with p =1/365 and n = 365

Hence

expected value = np =1

4 0

4 years ago

Antonius the chef wants to cook several batches of lasagna and spaghetti for his restaurant. He plans to use at least 4.54.5 kil

yaroslaw [1]

Answer: No he does not meet both of his expectation by cooking 10 batches of spaghetti and 4 batches of lasagna.

Step-by-step explanation:

Since here S represents the number of batches of spaghetti and L represents the total number of lasagna.

And, the chef planed to use at least 4.5 kilograms of pasta and more than 6.3 liters of sauce to cook spaghetti and lasagna.

Which is shown by the below inequality,

$0.3S+0.65L \geq 4.5$ ----------(1)

And, $0.25S+0.8L >6.3$ --------(2)

By putting S = 10 and L = 4 in the inequality (1),

$0.3\times 10+0.65\times 4 \geq 4.5$

⇒ $5.6\geq 4.5$ (true)

Thus, for the values S = 10 and L = 4 the inequality (1) is followed.

Again By putting S = 10 and L = 4 in the inequality (2),

$0.25\times 10+0.8\times 4 >6.3$

⇒ $5.7>6.3$ ( false)

But, for the values S = 10 and L = 4 the inequality (2) is not followed.

Therefore, Antonius does not meet both of his expectations by cooking 10 batches of spaghetti and 4 batches of lasagna.

4 0

3 years ago

Read 2 more answers