If a and b are angles lying in the 2nd quadrant such that cosa= -2/3 and cscb=2 find the following sin(a+b) and tan(a+b)

Answers

Answer 1

Both a and b lie in the second quadrant, which means

π/2 < a < π

π/2 < b < π

for which we have both cos(a) and cos(b) negative, while both sin(a) and sin(b) are positive. We're also given that

cos(a) = -2/3

csc(b) = 2   =>   sin(b) = 1/2

Now, recall the following identities:

• sin^2(x) + cos^2(x) = 1

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

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

• tan(x) = sin(x)/cos(x)

Now,

sin(a + b) = sin(a) cos(b) + cos(a) sin(b)

… = √(1 - cos^2(a)) (-√(1 - sin^2(b))) + cos(a) sin(b)

* * where we take the negative square root because we expect cos(b) < 0 * *

… = - √(1 - (-2/3)^2) √(1 - (1/2)^2) + (-2/3) (1/2)

… = - √(1 - 4/9) √(1 - 1/4) - (2/3) (1/2)

… = - √(5/9) √(3/4) - 1/3

… = - (√5/3) (√3/2) - 1/3

… = -√15/6 - 1/3

… = -(√15 + 2) / 6

From the above, we know sin(a) = √5/3 and cos(b) = -√3/2. Then

cos(a + b) = cos(a) cos(b) - sin(a) sin(b)

… = (-2/3) (-√3/2) - (√5/3) (1/2)

… = √3/3 - √5/6

… = (2√3 - √5) / 6

and so it follows that

tan(a + b) = sin(a + b) / cos(a + b)

… = (-(√15 + 2) / 6) / ((2√3 - √5) / 6)

… = - (√15 + 2) / (2√3 - √5)

… = - (√15 + 2) (2√3 + √5) / ((2√3 - √5) (2√3 + √5))

… = - (2√45 + 4√3 + √75 + 2√5) / (12 - 5)

… = - (6√5 + 4√3 + 5√3 + 2√5) / 7

… = - (8√5 + 9√3) / 7


Related Questions

please help, no links

Answers

Answer:

150

Step-by-step explanation:

Remark

The exterior angle = the sum of the two given interior angles. The first job is to solve for x and then use that to find the exterior angle.

Equation

83 + 6x + 7 = 15x              

Solution

Combine like terms

90 + 6x = 15x        Subtract 6x from both sides.

        6x     6x

90 = 9x                 Divide both sides by 9

90/9 = 9x/9

x = 10

Now the exterior angle = 15x

Exterior angle = 15*10

Exterior angle = 150

I think it’s 393.75 But not Sure can anyone confirm ? Or share the right answer

Answers

Answer:

$415.63

Step-by-step explanation:

it would have been 393.75, but he worked 5 hours overtime and got paid time and a half for it, meaning his normal pay plus half of it. (only for overtime tho).

so first calculate his normal pay:

40 × 8.75 = 350

then add overtime to it

8.75 × 5 = 43.75

43.75 × 1.5 = 65.625

65.625 + 350 = 415.625

round that and its 415.63!

This is worth my grade plz help 20pt

Answers

Answer:

C

Step-by-step explanation:

According to Math.way C would be the correct answer :)

question number nine answer

Answers

Answer:9

Step-by-step explanation:

Answer:

I think it's either A or D

Hey luvs!

The endpoints of AB are A(1,4) and B(5,-1). What are the coordinates of the point that divides AB in the ratio
2:3?

Answers

Answer:

I don't know I'm sorry.............

Solve for x.
x + 2 over 4 = 8​

Answers

[tex]\huge\text{Hey there!}[/tex]

[tex]\mathsf{\dfrac{x +2}{4}=8}[/tex]

[tex]\large\textsf{MULTIPLY 4 to BOTH SIDES}[/tex]

[tex]\mathsf{\dfrac{x +2}{4}\times4=8\times4}[/tex]

[tex]\large\textsf{CANCEL out: 4}\times\large\textsf{4.}[/tex]

[tex]\large\textsf{KEEP: 8}\times\large\textsf{4 because it helps you solve for x}[/tex]

[tex]\mathsf{8\times4=\bf 32}[/tex]

[tex]\large\text{New equation: \textsf{x + 32 = \bf 32}}[/tex]

[tex]\large\textsf{x + 2 = 32}[/tex]

[tex]\large\textsf{SUBTRACT 2 to BOTH SIDES}[/tex]

[tex]\mathsf{x +2-2=32-2}[/tex]

[tex]\large\textsf{CANCEL out: 2}-\large\textsf{2 because that gives you 0}[/tex]

[tex]\large\textsf{KEEP: 32}-\large\textsf{2 because that helps you solve for x}[/tex]

[tex]\large\textsf{New EQUATION: \mathsf{x = 32 - 2}}[/tex]

[tex]\mathsf{x = 32 - 2}[/tex]

[tex]\large\textsf{Simplify above and you have your result to this equation}[/tex]

[tex]\mathsf{32-2=\bf 30}[/tex]

[tex]\boxed{\boxed{\large\textsf{Answer: \huge \bf x =30}}}\huge\checkmark[/tex]

[tex]\large\text{Good luck on your assignment and enjoy your day!}[/tex]

~[tex]\frak{Amphitrite1040:)}[/tex]

What positive integer is closest to the value of the square root of 230 ?​

Answers

9514 1404 393

Answer:

  15

Step-by-step explanation:

Your calculator can tell you √230 ≈ 15.17. The closest integer is 15.

__

If you have memorized the squares of small integers, you know that 15² = 225 and 16² = 256. 230 is closer to 225 than to 256, so √230 will be closer to 15.

Matthew has a bag that contains orange chews, cherry chews, and lime chews. He
performs an experiment. Matthew randomly removes a chew from the bag, records
the result, and returns the chew to the bag. Matthew performs the experiment 24
times. The results are shown below:
A orange chew was selected 10 times.
A cherry chew was selected 11 times,
A lime chew was selected 3 times.

Answers

Answer: 13/24

Step-by-step explanation:

The experiment occurred 24 times orange or lime was selected 10+3=13

Probability the next chew will be orange or lime: 13/24

HELP ME PLEASEEEEEEEEEEEEEEEEEEE

Answers

Answer:

The second answer choice

Step-by-step explanation:

The pyramid shown is a triangular pyramid. A triangular pyramid consist of 4 faces; 1 triangular base and 3 triangular lateral faces.

Hence, the correct answer would be the second choice.

A bag contains eight white marbles, six red marbles and four blue marbles.
How many blue marbles must be added to the bag so that the probability
of choosing a blue marble is 1/2?
a. 6
b. 5
c. 10
d. 0

Answers

Answer:

c) 10

Step-by-step explanation:

you need to add the white and red marbles which would be 14.

then you subtract 14 by the amount of blue marbles.

Find the distance of the two given points (1,5) and (4,10)

Answers

Answer:

5.831

Step-by-step explanation:

Distance between both given points=Lenght=5.831

Which angle has a positive measure?

Answers

Answer:

what angles

Step-by-step explanation:

i do not see anything to solve

Solve for X (round to the nearest hundred)

Answers

Step-by-step explanation:

We use tangent because it uses opposite over adjacent.

So,

tan 33 = x/46

or

46 * tan 33 = x

Type this into the calculator and you get around 29.87

Nine years ago, Tarah opened a savings account with her bank. She started with a balance of $359 and has not made any withdrawals or deposits since then. If her interest rate is 8% each year, how much interest has accrued using simple interest?
What is Tarah's new total balance?

Answers

Answer:

$258.48

Step-by-step explanation:

Consider the triangle below

Answers

There is no picture

What is the answer for the four at the bottom?

Answers

What am I suppose to do so I can help you?

2 4/5*1 1/12=
Help plz it’s for grade recovery

Answers

Answer:

3.03 (if you're rounding to nearest hundredth, 3 if nearest whole/tenth.

That’s really hard but i will find the answer give me one second please .

which equation is not a linear function:
y=2x
y=x+2
y=x-2
y=x²

Answers

Answer:

Step-by-step explanation:

A linear equation can be written in the form

y = mx+b.

y = x² is not linear.

the final answer math

Answers

Answer:

$10.50

Step-by-step explanation:

$39.90 ÷ 3.8 pounds

= 10.50263157894735

after rounding, your answer must be 10.50

hope this helps.

If s =unit and A = 1652, what is the value of A, in square units?
___ square unit(s). (Input whole number only.)

Answers

1/4 x 1/4 = 1/16
1/16 x 16 = 1
A = 1

Plz help this is due today NO LINKS OR GROSS PICTURES OR I Will REPORT And please show work

It is not 480 480 is the incorrect answer

Answers

Answer:

2280 the volume

Step-by-step explanation:

So one box = 480

So then what about 6 boxes?

you do 480 x 6 =   2880

480+ 480+ 480+ 480+480+480= 2880

Help me guys find the solution please and thank you
4x+17=23

Answers

X = 1.50. Good luck!
The answer is: X = 1.5

I hope it’s helps you :)

Find indicated side of right triangle 45 percent 7

Answers

Answer:

a = 7

b = 7[tex]\sqrt{2}[/tex]

Step-by-step explanation:

in a 45-45-90° triangle, the length of legs to hypotenuse is 1 : [tex]\sqrt{2}[/tex]

Find the surface area and volume of the figure. Round to the nearest tenth.

Answers

surface area = 374 cm^2 and volume 384 cm^3. I think . try to go ok calculator.net

5th grade math. correct answer will be marked brainliest

Answers

The answer is b          

saddsadsadas

Answer:

B

Step-by-step explanation:

Cause he added 24.76 more pounds to the 3.6 pounds. So you can take 24+3=27 and you might think C, but 0.76+0.6 that equals more than 1, so 27+1=28, and B has 28 as its answer, so its B

B

what is AC? pls help 30 points if u awnser

Answers

Answer:

C. 6

Step-by-step explanation:

ΔADC and ΔACB are similar because two of their angles are congruent (∠ACD and ∠ABC, and ∠DAC and ∠CAB)

Because the sides are similar, you can create a proportion

[tex]\frac{AC}{AD}=\frac{AB}{AC}[/tex]

substitute the given values for the sides. AD=4 and AB=4+5=9

[tex]\frac{AC}{4}=\frac{9}{AC}[/tex]

cross multiply

[tex]AC^{2} =36[/tex]

take the square root of both sides

AC=6

I’ve done this, the answer was c


write the percent of each figure
that is shaded.

Answers

Answer:

1. 21%   2.  70%

Step-by-step explanation:

1. 21 out of 100 are filled in

2. 7/10 are filled in

In the diagram below, xy and z are tangent to 0. What is the measure of XZ?

Answers

Answer:

A. 130°

Step-by-step explanation:

Answer:130

Step-by-step explanation:

I just finished the quiz :)

Evaluate each series.
Help pls 50 points

Answers

Answer:

1. 2,555

2. 23.25

Step-by-step explanation:

1. 5+10+20+...

S9 = 5(2^9-1)/(2-1)

= 5(511) = 2,555

2. 12+6+3+1.5+0.75 = 23.25

Giving brainliest ; What is the mean of the data set? {20,1,14,14,9,8} Enter your answer in the box.

Answers

Answer:

11

Step-by-step explanation:

(20 + 1 + 14 + 14 + 9 + 8) / 6

= 66 / 6

= 11

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