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4vir4ik [10]
3 years ago
6

Can anyone help me with trig identities?

Mathematics
1 answer:
nevsk [136]3 years ago
6 0

Answer:

cosA = √(21/25)

Step-by-step explanation:

We know

sin²(A) + cos²(A) = 1

Next, we know that sin(A) = 2/5. Plugging that into our equation, we get

(2/5)² + cos²A = 1

4/25 + cos²A = 1

subtract 4/25 from both sides to isolate cos²A

cos²A = 1 - 4/25 = 25/25-4/25 = 21/25

square root both sides to get

cosA = √(21/25)

We do not include -√(21/25) in our possible answer for cosA because this is in quadrant 1, so cosA must be positive.

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John works Monday to Friday. He buys his lunch on his way to work. Each day John buys a sandwich, a bottle of water and a bag of
kipiarov [429]

Complete question

Shop A _________________ shop B £3

Any sandwich - £2.85 ___ sandwich, water crisp

A bottle of water - 60p

A bag of crisp - 85p

Answer:

£6.50, John is incorrect

Step-by-step explanation:

Number of working days = 5 = number of days meal is purchased

Total cost per meal, shop A :

£(2.85 + 0.60 + 0.85) = £4.3

Total cost for the week = 4.3 * 5 = £21.50

Total cost per meal cost Shop B = £3

Total cost for the week = 3 * 5 = £15

Difference :

£21.50 - £15 = £6.50

Hence, Amount John saves by buying from shop B is £6.50

Numbe

4 0
2 years ago
A recipe requires 4 cups of flour to make 12 servings and 7 cups of flour to make 21 servings. How many cups of flour is needed
grandymaker [24]

Answer:

6

Step-by-step explanation:

to get cups to servings multiply by 3

if you need 18 servings then divide by 3

6 0
3 years ago
The lateral area of a regular pentagonal pyramid is 75 square inches and the slant height is 10 inches. Find the length of each
Ksivusya [100]
I think it’s a if it’s not sorry :)
5 0
3 years ago
What is the solution of the inequality shown below?<br><br> w + 4 &gt; 0
Svetlanka [38]

Answer:

w>-4

Step-by-step explanation:

w+4>0

w+4-4>0-4

w>-4

7 0
3 years ago
How would i do this problem and show my work x+9= -12
boyakko [2]
To solve this problem just do the following, 
x+9=-12
   -9    -9
x=-21
Check
-21+9=-12 = True 

Hope this helps!=) 
5 0
3 years ago
Read 2 more answers
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