1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Andreas93 [3]
3 years ago
7

Find the exact value of cos 15°

Mathematics
2 answers:
Reil [10]3 years ago
5 0

Answer:

\frac{\sqrt{6}+\sqrt{2}  }{4}

Step-by-step explanation:

Using the difference formula for cosine and the exact values

cos45° = sin45° = \frac{\sqrt{2} }{2}, cos30° = \frac{\sqrt{3} }{2}, sin30° = \frac{1}{2}

cos(a - b) = cosacosb + sinasinb

Note 15° = 45° - 30°, thus

cos15°

= cos(45 - 30)°

= cos45°cos30° + sin45°sin30°

= (\frac{\sqrt{2} }{2} × \frac{\sqrt{3} }{2} ) + (\frac{\sqrt{2} }{2} × \frac{1}{2} )

= \frac{\sqrt{6} }{4} + \frac{\sqrt{2} }{4}

= \frac{\sqrt{6}+\sqrt{2}  }{4}

Zielflug [23.3K]3 years ago
3 0

Answer:

\frac{\sqrt{6} +\sqrt{2} }{4}

Step-by-step explanation:

You might be interested in
the scale of a scientific drawing is 1 cm = 2in. If the actual length of an object in the drawing was 4.5 inches, how long would
Citrus2011 [14]

Answer:  2.25

Step-by-step explanation:

1 cm/ 2 in = x/ 4.5 in

2x = 4.5 in

4.5/2 = x

2.25 = x

6 0
3 years ago
Need help......................
Lera25 [3.4K]
I don’t really know it sry
5 0
3 years ago
How would you solve this
nika2105 [10]
To find 10% you would just divide 200 by 10
=200/10
=20

hope this helped !
3 0
3 years ago
Please help with this
Assoli18 [71]

Answer:

the answer is 34567

Step-by-step explanation:

im not lying just to get points

8 0
3 years ago
The temperature is -14 degrees. Over the next three days, the temperature drops 5 degrees, then 3 degrees, and finally 1 degree.
Margaret [11]

Answer:

-23 degree

Step-by-step explanation:

=>-14-5-3-1

=>-23

5 0
3 years ago
Read 2 more answers
Other questions:
  • Morgan uses 1/4 of her supply of raisins to make a trail mix and 3/8 of her supply of raisins to make cookies.If Morgan uses 5 p
    15·1 answer
  • What times 8 eguals 100
    11·2 answers
  • What is 7/25 in decimal form
    10·1 answer
  • What is 2.1 yd/min=ft/s
    7·1 answer
  • A marketing company wants to know if people who like brand X soda also like brand Y potato chips. Which procedure is the most ap
    7·1 answer
  • What is -2/3 + 6 1/8 pls hurry i need help ❤️
    6·1 answer
  • Bev scored 540 points. This was 158 points more than Ike scored. How many points did Ike score?
    12·1 answer
  • If A(3,4) and B(10,4) are the end points of a diameter of circle "O", what is the area of the circle O
    11·1 answer
  • Katie operates a machine that makes 150 crayons per minute.
    5·2 answers
  • Please help me find W Z U
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!