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Ilia_Sergeevich [38]

3 years ago

7

Explain how the sum and difference formula cos(A+/- B) = cosA cosB -/+ sinA sinB could be useful?

2 answers:

Nadya [2.5K]3 years ago

7 0

You could find the exact value of cos of 15 degrees by using cos(45 - 30):-

cos(45 - 30) = cos 45cos30 + sin45 sin30 = 1 /sqrt2 * sqrt3/2 + 1/sqrt2* 1/2

serg [7]3 years ago

6 0

One way it's useful is in the application of phasors in physics. Phasors require you to add up vectors of two different angles, so the cosine angle addition formula can be used if you already know the cosine and sine of the original vector angles.

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A hostel having strength of 300 students requires on an average 36000 L of water per day. It has a tank measuring 10 m × 8 m × 9

Novosadov [1.4K]

Answer:

The water in the tank filled to capacity lasts 20 days.

Step-by-step explanation:

Total number of students in the hostel = 300

The average need of water per day = 36,000 L

The dimensions of the tank = 10 m × 8 m × 9 m

Now, the capacity of the tank = LENGTH X WIGHT X HEIGHT

= 10 m × 8 m × 9 m = 720 cubic meters

Now, $1m^{3} = 1,000L$

⇒ $720 m^{3} = 720 \times 1,000L = 720,000L$

So, the capacity of the tank = 720,000 L

and the average usage of water by 300 students = $= \frac{720,000 L}{36,000 L} = 20$

⇒ $\textrm{The number of days water lasts} = \frac{\textrm{Total capacity of the tank}}{\textrm{Average need of water per day}}$

or, number of days = 20

Hence, the water in the tank filled to capacity lasts 20 days.

3 0

3 years ago

Kyle mixes 45 grams of popcorn with 15 grams of powdered cheese. How much popcorn does Kylebuse per gram of cheese?

nekit [7.7K]

Answer:

B

Step-by-step explanation:

45 grams of popcorn/15 grams of cheese = 3 grams of popcorn per 1 gram of cheese

7 0

3 years ago

Any sample from a group of people will be representative of the entire group.<br><br> true<br> false

Inessa [10]

The answer would be false

4 0

3 years ago

Combine any like terms in the expression. If there are no like terms, rewrite the expression.

inn [45]

Good news: they are all like terms
9x + 5x -3x -8x = 3x

6 0

2 years ago

Read 2 more answers

Joann has a jug containing 128 ounces of milk. She drinks 14 ounces of milk each day. Enter the function f(x) that represents th

Tatiana [17]

Answer:

$f(x)=128-14x$

Step-by-step explanation:

So, we started out with 128 ounces of milk.

Each day, Joann drinks 14 ounces of milk.

Therefore, the amount of milk left over after x days is 14 times x subtracted from 128.

Therefore, our function is:

$f(x)=128-14x$

And we're done!

6 0

3 years ago