Help me to do this question plz plz plz ​

sin(x+y) - sin(x-y) - 1 = cos(2x)

sin(90) - sin(x-y) - 1 = cos(2x)

1 - sin(x-(90-x)) - 1 = cos(2x)

-sin(2x-90) = cos(2x)

-1*(sin(2x)cos(90) - cos(2x)sin(90)) = cos(2x)

-1*(sin(2x)*0 - cos(2x)*1) = cos(2x)

-1*(0 - cos(2x)) = cos(2x)

-1*(-cos(2x)) = cos(2x)

cos(2x) = cos(2x)

This confirms the identity is true.

Notice that throughout this proof, I only changed the left hand side.

On the 5th line, I used the identity sin(A-B) = sin(A)cos(B)-cos(A)sin(B).

Answer:

a)139°

Step-by-step explanation:

two co interior angles make one opposite exterior angle

49+90=139°

Answer: x = 6

Step-by-step explanation:

Sume 17 a ambos lados

5(3x-4)-17 + 17=5(x+8)-17 +17

Simplifica

5(3x-4)=5(x+8)

Expandir 5(3x -4) : 15x - 20

Expandir 5(x+8) : 5x +40

15x - 20 = 5x +40

Sume 20 a ambos lados

15x - 20 + 20 = 5x +40 +20

Simplifica

15x = 5x +60

Restar 5 de ambos lados

15x - 5x = 5x + 60 - 5x

Simplifica

10x = 60

Divide ambos lados entre 10

10x/10 = 60/10

Simplifica

x = 6

Answer:

She should first perform the operation in the parentheses, you can reference the order of the operations based on PEMDAS.

Step-by-step explanation:

1. parentheses operations

2. multiply 4 x 3

3. add the value you get from the parentheses with -7

4. with that value add it to the product of 4 and 3

Hope that helped! :)

Answer:

Subtraction

Explanation:-

[tex]( 1.25 -0.4) \div7+ 4 \times 3[/tex]

Using BODMAS Rule:-

In bracket, the operation subtraction should be performed first .

Answer:

Range = maximum number - minimum number

Range = 99 - 62 = 37

Answer:

37

Step-by-step explanation:

The range is the difference between the highest number and the smallest number.

Looking at the stem and leaf plot we can identify the largest and smallest number

Largest number: 99

Smallest number: 62

If range = largest number - smallest number then range = 99 - 62 = 37

Answer: Choice B

Open circle at 3. Shading to the right

========================================================

Work Shown:

3(8 - 4x) < 6(x - 5)

24 - 12x < 6x - 30

24 + 30 < 6x + 12x

54 < 18x

18x > 54

x > 54/18

x > 3

We use an open circle at 3 to indicate we don't include this endpoint as part of the solution. The solution set is everything larger than 3, so we shade to the right of this open circle.

Step-by-step explanation:

10 % of 2700 = 270

so he had 2970 rupee

20% of 2970 = 594

so customer have to pay 2970 + 594 = 3564

Answer:

x = 1 và 2       x= 1 and 2

Step-by-step explanation:

Đầu tiên trừ đi 1 để được 2x-3 nhỏ hơn -1 sau đó bạn lập phương trình bằng 2x-3 = -1 và 2x-3 = 1 để nhận được kết quả cuối cùng là 1 và 2 do đó x = 1 và 2

First subtract 1 to get 2x-3 is less then -1 then you let the equation equal 2x-3=-1 and 2x-3=1 to get a final answer of 1 and 2 therefore x=1 and 2

Answer:

That is the graph for y = -|x| + 3

Answer:

Triangle ACB =~ triangle DFE, by adding 6 units to each side of both triangles their relationship will not change. They are still similar.

Step-by-step explanation:

The answer isn't great in all honesty but it's been a long time since I took geometry and I don't 100% remember the proper way of stating it. Though I am 100% sure they stay similar.

Sorry couldn't be of more help but figured something was better then nothing

Answer:

I think b no. is the correct answer

Answer:

D. (5, –23)

Step-by-step explanation:

The vertex is in essence the turning point of the parabola y = x² − 10x + 2

the x coordinate of the turning point =  

                                                        =  

                                                        =  5

when x = 5, y = (5)² - 10(5) + 2

                     = -23

Thus coordinate or vertex is ( 5, -23)

5 right 23 down

Answer: 5

Step-by-step explanation:

⇒ (x - 4) = 1

⇒ x = 1 + 4

⇒ x = 5

Therefore value of x = 5

Answered by Gauthmath must click thanks and mark brainliest

Answer:

11

Step-by-step explanation:

If the set of numbers are not in least to greatest first set them up into their positions. But since this set is already in least to greatest we can go to the next step.

6, 7, 10, 12, 12, 13

Cross off all numbers until you get to the middle:

6, 7, 10, 12, 12, 13

Find the mean of the numbers in the middle:

10 + 12 = 22

22 / 2 = 11

The answer is 11

Hope this helped.

Answer:

11

Step-by-step explanation:

10+12=22

22÷2=11

median is equal to the middle number after being arranged in ascending order.

Answer:

90 degrees

Step-by-step explanation:

see image

make x A

y B

z C

AB=3 (given)

AC=9 (given)

measure of angel B or y, is 90

if

x= A

y= C

z= B

then the hypotenuse would be shorter than one of the legs

3<9

so B has to be the right angle (90 degrees)

Answer:

4/10 : 1/25

4/10 / 1/25 = 4/10 x 25/1 = 100/10 = 10.

10 can also be written as 10:1, so A is correct.

Hope this helps!

Answer

1 + 5 ÷ 5

This would equal 2, using BIDMAS.

In this question first you should find profit amount by using formula and you should use profit amount in profit percentage formula then you should calculate it

Answer:

Step-by-step explanation:

Given equation of the quadratic function is,

y = x² + 5x - 7

Convert this equation into vertex form,

y = x² + 2(2.5x) - 7

  = x² + 2(2.5x) + (2.5)² - (2.5)² - 7

  = (x + 2.5)²- 6.25 - 7

  = (x + 2.5)² - 13.25

Therefore, vertex of the function is → (-2.5, -13.25)

For the solutions,

y = 0

(x + 2.5)² - 13.25 = 0

x = (±√13.25) - 2.5

x = (±3.64) - 2.5

x = 1.14, -6.14

Solutions → (-6.14, 0) and (1.14, 0)

Answer:

y=3x - 1

Step-by-step explanation:

we are going to base the answer off of the y=mx+b form where m represents slope and b represents the y-intercept.

we know that b must be -1 because the line hits the y-axis when y is -1

this now leaves us with either the first or second choice

we then choose two points to find the slope. I am using (0,-1) and (1,2). If you count the boxes, the y-value increases by 3 as the x-value increases by 1. So the slope is 3/1 or 3.

so then we know the answer is y=3x-1

hope this helps

Answer:

x = 32 feet

Step-by-step explanation:

By applying tangent rule in ΔACD,

tan(40°) = [tex]\frac{\text{Opposite side}}{\text{Adjacent side}}[/tex]

             = [tex]\frac{AB+AC}{CD}[/tex]

             = [tex]\frac{x+BC}{87}[/tex]

x + BC = 73 -----(1)

By applying tangent rule in ΔBCD,

tan(25°) = [tex]\frac{BC}{CD}[/tex]

             = [tex]\frac{BC}{87}[/tex]

BC = 40.57

By substituting the value of BC in equation (1),

x + 40.57 = 73

x = 32.43

x ≈ 32 feet

Answer:

My best guess rn is the first option

Step-by-step explanation:

the last dude had it close but it was basically flipped as you can tell.

The answer is (C) [tex]R_2=\frac{R_TR_1}{(R_1-R_T)}[/tex]

We need to make [tex]R_2[/tex] the subject of the formula [tex]R_T=\frac{R_1R_2}{R_1+R_2}[/tex]

First remove the denominator by multiplying both sides by the binomial [tex](R_1+R_2)[/tex]

[tex]R_T\times (R_1+R_2)=\frac{R_1R_2}{R_1+R_2}\times(R_1+R_2)\\\\R_TR_1+R_TR_2=R_1R_2[/tex]

Arrange all terms containing [tex]R_2[/tex] on one side

[tex]R_1R_2-R_TR_2=R_TR_1[/tex]

Factor out [tex]R_2[/tex] from the LHS

[tex]R_2(R_1-R_T)=R_TR_1[/tex]

Finally, divide both sides by the binomial [tex](R_1-R_T)[/tex] to leave [tex]R_2[/tex]

[tex]R_2(R_1-R_T)\times\frac{1}{(R_1-R_T)}=R_TR_1\times\frac{1}{(R_1-R_T)}\\\\R_2=\frac{R_TR_1}{(R_1-R_T)}[/tex]

Learn more about change of subject of formula here: https://brainly.com/question/343660

Step-by-step explanation:

here's the answer to your question

Answer:

the answer is 21

Step-by-step explanation:

Answer:

36² metres

Step-by-step explanation:

I'm assuming you mean 6 metre wide/long floor. Area is L*W so 6*6

Answer:

see below

Step-by-step explanation:

The domain is the values that the input takes

The values go from 0 to 7

0≤x≤7

This is the time from the initial launch until the object hits the ground

Answer:

a) 16, 19, 22, 25, 28, 31, 34, 37, 40

b) 1, 3, 9, 27, 81, 243, 729, 2187

a) Add 3 on every number.

b) Multiply every number by 3.

Answer:

s(2) = 17 cm

Step-by-step explanation:

We are told that the velocity function is;

v(t) = 6t² + 4t − 5 cm/sec

Integral of velocity gives distance.

Thus;

s(t) = ∫v(t) = ∫6t² + 4t − 5

s(t) = 2t³ + 2t² - 5t + c

We are told that s(0)=3 cm

Thus;

s(0) = 2(0)³ + 2(0)² - 5(0) + c = 3

Thus; c = 3

Thus;

s(t) = 2t³ + 2t² - 5t + 3

At t = 2 secs

s(2) = 2(2)³ + 2(2)² - 5(2) + 3

s(2) = 17 cm