find the exact value of 6cos(105°)​

Answers

Answer 1

Answer:

[tex]-\frac{3(\sqrt{6}-\sqrt{2})}{2}\text{ or } \frac{-3\sqrt{6}+3\sqrt{2}}{2}}\text{ or }\frac{3(\sqrt{2}-\sqrt{6})}{2}[/tex]

Step-by-step explanation:

There are multiple ways to achieve and even express the exact answer to this problem. Because the exact value of [tex]6\cos(105^{\circ}})[/tex] is a non-terminating (never-ending) decimal, it does not have a finite number of digits. Therefore, you cannot express it as an exact value as a decimal, as you'd either have to round or truncate.

Solution 1 (Cosine Addition Identity):

Nonetheless, to find the exact value we must use trigonometry identities.

Identity used:

[tex]\cos(\alpha +\beta)=\cos \alpha \cos \beta-\sin \alpha \sin \beta[/tex]

Notice that [tex]45+60=105[/tex] and therefore we can easily solve this problem if we know values of [tex]\cos(45^{\circ})[/tex], [tex]\cos(60^{\circ})[/tex], [tex]\sin (45^{\circ})[/tex], and [tex]\sin(60^{\circ})[/tex], which is plausible as they are all key angles on the unit circle.

Recall from either memory or the unit circle that:

[tex]\cos(45^{\circ})=\sin(45^{\circ})=\frac{\sqrt{2}}{2}[/tex] [tex]\cos(60^{\circ})=\frac{1}{2}[/tex] [tex]\sin(60^{\circ})=\frac{\sqrt{3}}{2}[/tex]

Therefore, we have:

[tex]\cos(105^{\circ})=\cos(45^{\circ}+60^{\circ}}),\\\cos(45^{\circ}+60^{\circ}})=\cos 45^{\circ}\cos 60^{\circ}-\sin 45^{\circ}\sin 60^{\circ},\\\cos(45^{\circ}+60^{\circ}})=\frac{\sqrt{2}}{2}\cdot \frac{1}{2}-\frac{\sqrt{2}}{2}\cdot \frac{\sqrt{3}}{2},\\\cos(105^{\circ})=\frac{\sqrt{2}}{4}-\frac{\sqrt{6}}{4},\\\cos(105^{\circ})={\frac{-\sqrt{6}+\sqrt{2}}{4}}[/tex]

Since we want the value of [tex]6\cos 105^{\circ}[/tex], simply multiply this by 6 to get your final answer:

[tex]6\cdot {\frac{-\sqrt{6}+\sqrt{2}}{4}}=\frac{-3\sqrt{6}+3\sqrt{2}}{2}}=\boxed{\frac{3(\sqrt{2}-\sqrt{6})}{2}}[/tex]

Solution 2 (Combination of trig. identities):

Although less plausible, you may have the following memorized:

[tex]\sin 15^{\circ}=\cos75^{\circ}=\frac{\sqrt{6}-\sqrt{2}}{4},\\\sin 75^{\circ}=\cos15^{\circ}=\frac{\sqrt{6}+\sqrt{2}}{4}[/tex]

If so, we can use the following trig. identity:

[tex]\cos(\theta)=\sin(90^{\circ}-\theta)[/tex] (the cosine of angle theta is equal to the sine of the supplement of angle theta - the converse is also true)

Therefore,

[tex]\cos (105^{\circ})=\sin (90^{\circ}-105^{\circ})=\sin(-15^{\circ})[/tex]

Recall another trig. identity:

[tex]\sin(-\theta)=-\sin (\theta)[/tex] and therefore:

[tex]\sin (-15^{\circ})=-\sin (15^{\circ})[/tex]

Multiply by 6 to get:

[tex]6\cos (105^{\circ})=-6\sin (15^{\circ})=-6\cdot \frac{\sqrt{6}-\sqrt{2}}{4}=\boxed{-\frac{3(\sqrt{6}-\sqrt{2})}{2}}[/tex] (alternative final answer).


Related Questions

f(X) = 10x^3 find inverse

Answers

1000 is you answer
Or
10x10x10
Or
10/3

Answer: [tex]y=\sqrt[3]{\frac{x}{10} }[/tex]

Step-by-step explanation:

[tex]f(x)=10x^{3}\\y=10x^{3}[/tex]

switch the x and y:

[tex]x=10y^{3}[/tex]

Now solve for y:

[tex]x=10y^{3} \\\frac{x}{10} =y^{3} \\\sqrt[3]{\frac{x}{10} } =y\\[/tex]

Therefore, the inverse of that function is: [tex]y=\sqrt[3]{\frac{x}{10} }[/tex]

a + b·c = a + c·b is an example of the associative property.

Answers

Answer:

yes , This is an example of the associative property.

Step-by-step explanation:

round 6.8 to nearest hundredth

Answers

Answer:

6.8

Step-by-step explanation:

The number is already rounded to the nearest tenth and hundredth.

i gave someone a Brainliest pls

Answers

Answer:

i think the mistake was in step 1

Step-by-step explanation:

find the measures of m and n.

Answers

Answer:

m = 4

n = 5

Step-by-step explanation:

[tex]m + 8 = 3m\\\\m - 3m = - 8\\\\-2m = - 8\\\\m = 4[/tex]

[tex]2n - 1 = 9 \\\\2n = 9 + 1\\\\2n = 10\\\\n = 5[/tex]

When Claire chooses a piece of fruit from a fruit bowl, there is a 22% chance that it will be a plum, an 18%
chance that it will be an orange, and a 60% chance that it will be an apple. Which type of fruit is she least likely
to choose?

Answers

Answer:

Orange

Step-by-step explanation:

As the chance of choosing orange is 18% which is the least.

verify that whether -2 and 3 are zeroes of the polynomial x^2-x=6
PLEASE HELP​

Answers

Answer:

Both give remainder 0 for the polynomial

Step-by-step explanation:

p(-2) = (-2)² - (-2) - 6

= 6 - 6 = 0

p(3) = (3)² - 3 - 6

= 9 - 9 = 0

An 8-oz bottle of hair spray costs $4.46. Find the unit price in cents per ounce

Answers

Answer:

55.75 cents per ounce

Step-by-step explanation:

Take the cost and divide by the number of ounces

We want cents per ounce so change dollars to cents

446 / 8

55.75 cents per ounce

Select the correct answer from each drop-down menu. Julie invests $200 per month in an account that earns 6% interest per year, compounded monthly. Leah invests $250 per month in an account that earns 5% interest per year, compounded monthly. After 10 years, Julie's account balance will be After 10 years, Leah's account balance will be After 10 years, will have more money in her account.

the answer: $32,776 / $38,821 / leah​

Answers

Answer:

After 10 years, Julie's account balance will be $ 363.88 and Leah's account balance will be $ 411.75, thus Leah will have more money in her account.

Step-by-step explanation:

Since Julie invests $ 200 per month in an account that earns 6% interest per year, compounded monthly, and Leah invests $ 250 per month in an account that earns 5% interest per year, compounded monthly, to determine the amount of each after 10 years, the following calculations must be performed:

200 x (1 + 0.06 / 12) ^ 10x12 = X

200 x 1.005 ^ 120 = X

200 x 1.8193 = X

363.88 = X

250 x (1 + 0.05 / 12) ^ 10x12 = X

250 x 1.00416 ^ 120 = X

250 x 1.647 = X

411.75 = X

Therefore, after 10 years, Julie's account balance will be $ 363.88 and Leah's account balance will be $ 411.75, thus Leah will have more money in her account.

The sum of 5 consecutive integers is 505. What is the second number in this sequence?

Answers

Answer:

The second number is 100.

Step-by-step explanation:

Let the first integer be x.

Then since the five integers are consecutive, the second integer will be (x + 1), the third (x + 2), fourth (x + 3), and the fifth (x + 4).

They total 505. Hence:

[tex]\displaystyle x+(x+1)+(x+2)+(x+3)+(x+4)=505[/tex]

Solve for x. Combine like terms:

[tex]5x+10=505[/tex]

Subtract 10 from both sides:

[tex]5x=495[/tex]

And divide both sides by five. Hence:

[tex]x=99[/tex]

Thus, our sequence is 99, 100, 101, 102, and 103.

The second number is 100.

A modified roulette wheel has 36 slots. One slot is​ 0, another is​ 00, and the others are numbered 1 through 34​, respectively. You are placing a bet that the outcome is an even number.​ (In roulette, 0 and 00 are neither odd nor​ even.) a. What is your probability of​ winning?

Answers

Answer:

[tex]P(win) = 0.4722[/tex]

Step-by-step explanation:

Given

[tex]n = 36[/tex] --- slots

[tex]Even = 17[/tex] i.e. even numbers between 1 and 34 (inclusive)

Required

[tex]P(win)[/tex]

The probabiity of winning is the number of even numbers divided by the total slot;

i.e.

[tex]P(win) = \frac{Even}{n}[/tex]

So, we have:

[tex]P(win) = \frac{17}{36}[/tex]

[tex]P(win) = 0.4722[/tex]

Please help me. A) vertical angle. B) complementary angle. C) supplementary angle. D) none of the above

Answers

(C)

Step-by-step explanation:

The sum of angles a and b is 180°, which make the two supplementary angles.

Identify the quantities that are equivalent to 250 meters.

Ratio Conversion Table
kilometer (km) : meter (m) 1 : 1,000
meter (m) : centimeter (cm) 1 : 100
centimeter (cm) : millimeter (mm) 1 : 10

Answers

Answer:

1. Convert all measurements to meters:

2.5km * 1,000 = 2,500m;.250km * 1,000 = 250m; 2,500cm / 100 = 25m

25,000cm / 100 = 250m; 250mm / 1,000 =.25m

2.) Compare the converted measurements. Therefore, the quantities that are equivalent to 250m are:

.250km; 25,000cm

Step-by-step explanation:


The length of a rectangle is 12 m and its diagonal is 15 m. find
the breadth and area of the rectangle.

Answers

Answer:

108 square metres

Step-by-step explanation:

A=√d square - l square

here

A = area

d= diagonal

l= length

Please Help
Solve 3(x+2)-4x=8

Answers

Hello!

3(x + 2) - 4x = 8 <=>

<=> 3x + 6 - 4x = 8 <=>

<=> -x + 6 = 8 <=>

<=> -x = 8 - 6 <=>

<=> -x = 2 <=>

<=> x = -2

Good luck! :)

3(x+2)-4x=8
3x+6-4x=8
-x+6=8
-x=2
x= -2

I didn't understand this to be honest I thought I had to find what jm and lm were together and then subtract from the whole total...but ended up being wrong. whats the correct answer?​

Answers

Answer:

The correct answer is 3x-2

Step-by-step explanation:

It gives you the expression for JM and LM, and it asks for JL. Therefore, if you take away LM from JM, you are left with JL. You must subtract 2x-6 from 5x-8.

∴5x-8-(2x-6)

Do not forget to distribute the negative since you are subtracting, so instead of subtracting 6 from 8, you will be adding 6 to 8 because two negatives make a positive.

A rectangle is four times as long as it is wide. If it has an area of 36 square inches, what are its dimension?
a. 6 by 6
c4 by 9
b. 3 by 12
d. 4 and 8

Answers

Answer:

C

Step-by-step explanation:

here in the question it is given that it is four times as long as wide and its area is 36 square inches

now as we onow 3×4 =12

therefore here the side becomes four time

now area of rectangle is equal to 12 ×3 =36

Someone please help me ASAP!

Answers

Answer:

The 3rd

Step-by-step explanation:

If x goes to infinity, f(x) goes to infinity too:

[tex]lim \: \frac{2 {x}^{2} }{3x - 1} = lim \frac{2x}{3 - \frac{1}{x} } = \frac{ 2 \times \infty }{3 - 0} = \infty [/tex]

8. When someone buys a ticket for an airline flight, there is a 0.0995 probability that the person will not show up for the flight. An agent for Air America wants to book 24 people on an airplane that can seat only 22. If 24 people are booked, find the probability that not enough seats will be available. You must show your work using a calculator function to receive credit.

Answers

Answer:

0.2952

Step-by-step explanation:

Not enough seats will be available if 23 or 24 people show up.

Required probability = 24C24(0.9005)24 + 24C23(0.9005)23*0.0995 = 0.2952

a drum has a diameter of 10 inches. find the area of the top of the drum. use 3.14 for pi.
.
.
.
Please show to work too. Thank you.

Answers

Answer:

My answer is 78.55

Step-by-step explanation:

I've given the steps. Hope it really helps

Answer: 78.5 inches

Step-by-step explanation:

Area = Pi x r x r

Diameter = 10 in

Radius = 5 in

314/100 x 5 x 5 = 314/4

314/4 = 78.5

= 78.5 inches

I'm not sure how to do this so I'm just asking for help.

Answers

Answer:

C

Step-by-step explanation:

In ∆DEG, we are given that all the three angles are congruent.

This means that all the three angles have equal measure. Thus,

<D = <E = <F

An equilateral triangle has equal angle measure. ∆DEF is an equilateral triangle.

Since the sum of a triangle is 180°, therefore, each angle in ∆DEF = 60°

m<D = 60°

Side CA of the right triangle CAT is 3cm long. The hypotenuse is 5cm long. How many
square centimeters is the area of CAT?

Answers

Answer:

8

Step-by-step explanation:

By taking the number "3" and plus together with the number 5

If one side of the triangle is 3 cm, and the hypotenuse is 5cm, then the other side is 4cm because of Pythagorean triples. Or you can use the Pythagorean theorem which is a^2+b^2=c^2. In this case, c=5, a=3. So it would be 9+b^2=25. b^2=16, and b=4. Then you find the area of the triangle. The formula for area of any triangle is height times base divided by two. (h times b)/2. So the height and the base are 3 and 4. 3 times 4=12, and 12 divided by 2 is 6.
So the area of CAT is 6 cm squared.

Find the volume of the cone. Round to the nearest hundredth.

Answers

Answer:

Step-by-step explanation:

volume of cone=1/3 πr²h

=1/3×π×5²×11

=275/3 ×3.14

≈287.33 in³

How to solve it and explain it

Answers

Answer:

28.27 in²

Step-by-step explanation:

The equation for the area of a circle is A = π[tex]r^{2}[/tex]. However, we got the diameter.

diameter = 2(radius), so:

A = [tex]\frac{1}{4}[/tex]πd².

A = 1/4 * π * 6² ≈ 28.27433

What is the length of my
?
M
3x
X + 8
7639
630
N
¿
O
A. 8
B. 4
C. 16
a
D. 12

Answers

Answer:

The length of MN is 4

Choose B

Question 8 of 9
Use a calculator to find the correlation coefficient of the data set.

у
2
15
6
13
7
8
12
X
15
13
9
8
5
A. -0.909
B. 0.909
C. 0.953
D. -0.953

Answers

Actual data table :

X __ y

2 15

6 13

7 9

8 8

12 5

Answer:

0.953

Step-by-step explanation:

The question isnt well formatted :

The actual data:

X __ y

2 15

6 13

7 9

8 8

12 5

Using a correlation Coefficient calculator, the correlation Coefficient obtained by fitting the data is 0.953 which depicts a strong linear correlation between the x and y variable. This shows that the value of y increases with a corresponding increase in x values and vice versa.

In a test of a heat-seeking rocket, a first rocket is launched at 2000 fts and the heat-seeking rocket is launched along the same flight path 20 s later at a speed of 3000 fts. Find
the timest, and t, of flight of the rockets until the heat-seeking rocket destroys the first rocket
What are the times of the flight?

Answers

Answer:

Time of flight of first rocket = 60 seconds

Time of flight of second rocket = 40 seconds

Step-by-step explanation:

Let the time of flight of first rocket be t1.

Since the second rocket is launched 20 seconds later, then it means that;

t1 = t2 + 20

Where t2 is the time of flight of the second rocket.

When destruction has occurred, it means that both of the rockets would have covered the same distance.

We know that;

Distance = speed × time

Thus;

2000t1 = 3000t2

We know that t1 = t2 + 20

Thus;

2000(t2 + 20) = 3000t2

2000t2 + 40000 = 3000t2

3000t2 - 2000t2 = 40000

1000t2 = 40000

t2 = 40000/1000

t2 = 40 seconds

Thus;

t1 = 40 + 20

t1 = 60 seconds

Complete the following statement.

Answers

Answer:

Hello dude

[tex] - 1 \frac{21}{24} + 1 \frac{22}{24} = + \frac{1}{24} [/tex]

so it's positive

HAVE A NİCE DAY

Step-by-step explanation:

GREETİNGS FROM TURKEY ツ

Which problem has a greater (bigger) answer? Solve both, choose the one that has the bigger answer and explain (1-2 sentences) how you found your
answer.
1) (2 + 3) (5 + 5)
2)2 + 3 x 5 + 5 =



I need so much helppppp pleaseeeee

Answers

Answer:

Problem 1 has a greater answer.

Step-by-step explanation:

Solve problem 1 using the order of operatiobs PEMDAS (Parentheses, Exponents, multiplication/division, and addition/subtraction):

Multiplication/division depends from left to right of the expression, the same goes to addition/subtraction.

(2 + 3) (5 + 5)

= (5)(10)

= 50

SOLVE problem 2 using PEMDAS:

2 + 3 x 5 + 5

= 2 + 15 + 5

= 17 + 5

= 22

Answer 1 (50) compared to Answer 2 (22):

50 > 22

HOPE THIS HELPS!

On a coordinate plane, a line goes through points (negative 1, 0), (0, 1), and (1, 2). Which table goes with the graph?

Answers

Answer:

Table B

Step-by-step explanation:

correct on edge :)

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