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
blsea [12.9K]
3 years ago
6

Find the exact value of sin –255°.

Mathematics
1 answer:
alekssr [168]3 years ago
8 0

Answer:

sin(-255°) = √2 + √6/4

Step-by-step explanation:

We need to find sin -255°

We know that sin(-a) = - sin(a)

so, sin(-255°) = - sin 255°

We know that 180° + 75° = 255°

Now we can write sin(255°) = sin(180° + 75°)

We can use the identity:

sin(x+y) = sin(x) cos(y)+cos(x)sin(y)

x = 180° , y = 75°

Solving,

sin(x+y) = sin(x) cos(y)+cos(x)sin(y)

sin(180° + 75°) = sin(180°) cos(75°)+cos(180°)sin( 75°)

sin(180°)  = 0

cos(75°) = √6 -√2/4

cos(180°) = -1

sin( 75°) = √2 + √6/4

Putting values,

sin(180° + 75°) = 0 (√6 -√2/4) + (-1)(√2 + √6/4)

sin(180° + 75°) = -(√2 + √6/4)

We know that sin(-255°) = -sin(255°)

Putting value of sin(255°)

sin(-255°)  = -(-(√2 + √6/4))

sin(-255°) = √2 + √6/4

You might be interested in
PLEASE HELP!!
PSYCHO15rus [73]

<u><em>Answer:</em></u>

The bird is approximately 9 ft high up in the tree

<u><em>Explanation:</em></u>

The required diagram is shown in the attached image

Note that the tree, the cat and the ground form a right-angled triangle

<u>Therefore, we can apply special trigonometric functions</u>

<u>These functions are as follows:</u>

sin(\alpha)=\frac{opposite}{hypotenuse} \\ \\ cos(\alpha)=\frac{adjacent}{hypotenuse} \\ \\tan(\alpha)=\frac{opposite}{adjacent}

<u>Now, taking a look at our diagram, we can note the following:</u>

α = 25°

The opposite side is the required height (x)

The adjacent side is the distance between the cat and the tree = 20 ft

Therefore, we can use the <u>tan function</u>

<u>This is done as follows:</u>

tan(\alpha)=\frac{opposite}{adjacent}\\ \\ tan(25)=\frac{x}{20}\\ \\x=20tan(25) = 9. 32 ft which is 9 ft approximated to the nearest ft

Hope this helps :)

5 0
3 years ago
Joe's gas tank is 1/4 full. After he buys 6 gallons of gas, it is 5/8 full. How many gallons can Joe's tank hold?
Korolek [52]

Answer:

Amount of gas that can be hold by Joe's tank = 16 gallons.

Step-by-step explanation:

Given that Joe's gas tank is 1/4 full. After he buys 6 gallons of gas, it is 5/8 full. Now we need to find about how many gallons can Joe's tank hold.

So let's find change that happened after filling the gas.

Change = (5/8 full) - (1/4 full)

Change = (5/8 - 1/4)  full

Change = (5/8 - 2/8)  full

Change = (5 - 2)/8  full

Change = 3/8  full

So that means 3/8 full happens in 6 gallons

then 1 full will happen in 6/(3/8) gallons = 6*(8/3) gallons = 48/3 gallons = 16 gallons

So the amount of gas that can be hold by Joe's tank = 16 gallons.

3 0
3 years ago
Nov 09, 17:58:28 AM
Marianna [84]
The percent discount is 30%.
If you multiply $32 by .30, you will get $9.60. That is the amount of the discount. If you subtract $9.60 from $32, you will get $22.40 which is what he paid before tax. Therefore the percent discount is 30%.
7 0
3 years ago
Which best describes what is happening in section b ?
levacccp [35]
D, he is moving at a constant spees
3 0
3 years ago
A- 13<br> B- 26 <br> C- 52<br> D- there is not enough information
Yakvenalex [24]

Answer:  the anwser is A. 13


7 0
3 years ago
Other questions:
  • Bella’s shoe is more or less than one yard?
    8·1 answer
  • Please Answer These!
    9·1 answer
  • Find the value of x. If necessary, round to the nearest tenth
    6·1 answer
  • As part of a screening process, computer chips must be operated in an oven at 145 °C. Ten minutes after starting, the temperatur
    8·1 answer
  • Which of the following expressions is equivalent to a^3 + b^3?
    12·1 answer
  • Raju is cycling at a speed of 30km/h. He applies brakes and stops at a junction in 10s. Calculate the acceleration.
    15·1 answer
  • Courtney save $6.18 each week. How much<br> will Courtney have saved after 14 weeks?
    10·1 answer
  • Simplify.<br> 1/2(4x-10)
    9·1 answer
  • 3=2 1/6 + ____<br><br><br> Please help or explain I’m confused!
    9·2 answers
  • At a community fund raiser event, bracelets cost $3 and necklaces cost $6. Complete the patterns in
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!