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

2 answers:

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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Mancini's Pizzeria sells four types of pizza crust. Last week, the owner tracked the number sold of each type, and this is what

Citrus2011 [14]

<em>The complete exercise with the answer options is as follows:</em>

Mancini's Pizzeria sells four types of pizza crust. Last week, the owner tracked the number sold of each type, and this is what he found.

Type of Crust Number Sold

Thin crust 364

Thick crust 240

Stuffed crust 176

Pan style 260

Based on this information, of the next 3000 pizzas he sells, how many should he expect to be thick crust? Round your answer to the nearest whole number. Do not round any intermediate calculations.

Answer:

692 thick crust pizzas

Step-by-step explanation:

With the data given in the exercise, we must first find the total number of pizzas, then we must find the proportion between the thick crust pizzas and the total number of pizzas, finally we must propose a rule of three to find the new proportion of crust pizzas thick on a total of 3000 pizzas.

Type of Crust Number Sold

Thin crust 364

Thick crust 240

Stuffed crust 176

Pan style 260

total pizzas : 1040

Now we must calculate for 3000 pizzas how much would be the total of thick crust pizzas.For that we must use the relationship found, that is, in 1040 pizzas there are 240 thick crust pizzas

1040→240

3000→x

x= $\frac{3000x240}{1040}$ = 692