help me plz i’ll give brainlest

Answer:

The two rules we need to use are:

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

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

And we also know that:

sin^2(a) + cos^2(a) = 1

To solve the relations, we start with the left side and try to construct the right side.

a) Sin(3*A) = sin (2*A + A) = sin(2*A)*cos(A) + sin(A)*cos(2*A)

sin(A + A)*cos(A) + sin(A)*cos(A + A)

(sin(A)*cos(A) + sin(A)*cos(A))*cos(A) + sin(A)*(cos(A)*cos(A) - sin(A)*sin(A))

sin(A)*cos^2(A) + sin(A)*cos^2(A) + sin(A)*cos^2(A) - sin^3(A)

3*sin(A)*cos^2(A) - sin(A)*sin^2(A)

sin(A)*(3*cos^2(A) - sin^2(A))

Now we can add and subtract 4*sin^3(A)

sin(A)*(3*cos^2(A) - sin^2(A)) + 4*sin^3(A) -  4*sin^3(A)

sin(A)*(3*cos^2(A) + 3*sin^2(A)) - 4*sin^3(A)

sin(A)*3*(cos^2(A) + sin^2(A)) - 4*sin^3(A)

3*sin(A) - 4*sin^3(A)

b) Here we do the same as before:

cos(3*A) = 4*cos^3(A) - 3*cos(A)

We start with:

Cos(2*A + A) =  cos(2*A)*cos(A) - sin(2*A)*sin(A)

= cos(A + A)*cos(A) - sin(A + A)*sin(A)

= (cos(A)*cos(A) - sin(A)*sin(A))*cos(A) - ( sin(A)*cos(A) + sin(A)*cos(A))*sin(A)

= (cos^2(A) - sin^2(A))*cos(A) - sin^2(A)*cos(A) - sin^2(A)*cos(A)

= cos^3(A) - 3*sin^2(A)*cos(A)

=  cos(A)*(cos^2(A) - 3*sin^2(A))

now we subtract and add 4*cos^3(A)

= cos(A)*(cos^2(A) - 3*sin^2(A)) + 4*cos^3(A) - 4*cos^3(A)

= cos(A)*(-3*cos^2(A) - 3*sin^2(A)) + 4*cos^3(A)

= cos(A)*(-3)*(cos^2(A) + sin^2(A)) + 4*cos^3(A)

= -3*cos(A) + 4*cos^3(A)

No.of sides=4

sum of angle of quadrilateral

=(n-2)*180°

=(4-2)*180°

=2*180°

=360°

Answer:

7/9 < 5/6

Step-by-step explanation:

The denominator is the common factor of the denominators

That is 54

So we have

7/9 * 6/6 = 42/54

5/6 * 9/9 = 45/54

So, the relation we have is that;

7/9 < 5/6

Answer:

B

Step-by-step explanation:B

Answer:

the answer to this question is B

Answer:

I believe the answer is O2

Answer:

A. Correct

B. Incorrect

C. Incorrect

D. Incorrect

Step-by-step explanation:

B, C, and D are compounds rather than elements

Answer:

729 * 10^-45

Step-by-step explanation:

Here, we want to expand the value based on the exponent

We have the power multiplying every term in the bracket

That would be;

9^3•10^-45

= 729 * 10^-45

Answer:

A change from 64 to 80 represents a positive change (increase) of 25%

Step-by-step explanation:

Answer:

x=1120-d

Step-by-step explanation:

Answer:

x = 1120 - d

Step-by-step explanation:

Hi there!

We can simplify this using orders of operations.

First, subtract 125 from both sides to get x + d = 1120.

To isolate x, just subtract d from both sides.

If you give me a value for d, i can solve the full problem.

I hope this helps!

Answer:

D

Step-by-step explanation:

Question:On Saturdays. Eve earns $14. per hour for yard work and charges an extra amount for supplies/gas money to get there. Look at the table. Choose the linear function f Eve can use to determine her pay, where x is in hours and f(x) is her pay in dollars.

Answer: The answer would be D because she gets payed $14 and hour so you would plug the hours she work into the letter x.

Answer:

Step-by-step explanation:

the quadratic expression is

2x^2+9x-7

this is the only one

Answer:

2x^2+9x-7

Step-by-step explanation:

Answer:

It’s D bro

Step-by-step explanation:

I’m doing the exact test rn it’s d trust

Answer:

C or D, but mostly D

Step-by-step explanation:

It's either C or D because I know the intercepts are 0 and 18. It says where X is the width so My final Answer would be D

Answer:

21 years

Step-by-step explanation:

Answer:

5d

Step-by-step explanation:

five time a number d

5 x d

5d

Answer:the population of brook trout

Step-by-step explanation:

Answer:

x=20

Step-by-step explanation:

x+2x+x+10=90

4x+10=90

4x=90-10

4x=80

x=80/4

x=20

Answer:

a dog

Step-by-step explanation:

Answer:

Dunno...Dog-man?

Step-by-step explanation:

Lemme think about that

Answer:

4 hours

Step-by-step explanation:

Answer:

im not 100% sure but i think its false

Step-by-step explanation:

Answer:

1.25*10-3m^3

Step-by-step explanation:

1kg petrol has density of 800kg/m3 find its volume in cm 3

Given data

mass m= 1kg

density = 800kg/m3

Required

The volume v

We know that

density= mass/volume

so

Volume= mass/density

substute

Volume= 1/800

volume=1.25*10-3m^3

Hence the volume is 1.25*10-3m^3

Answer:

4=b

Step-by-step explanation:

3b+3+1=4b

3b+4=4b

-3b    -3b

4=b

Answer:

would use the Trig Method.

Step-by-step explanation:

Answer:

D

Step-by-step explanation:

Step-by-step explanation:

you can use the app photo math or mathaway. its help alot the app also explains the work

Answer:

1350

Step-by-step explanation:

Hope this helps!

Answer:e

Step-by-step explanation:

Answer:

5805

Step-by-step explanation:

Answer:

[tex] (x, \: \: y) = (4, \: \: - \frac{1}{4} )[/tex]

Step-by-step explanation:

[tex] \frac{1}{4} x + \cancel{ 1 \frac{1}{2} y} = \frac{5}{8}...(1) \\ \\ \frac{3}{4} x - \cancel{ 1 \frac{1}{2} y} = 3 \frac{3}{8} ...(2) \\ - - - - - - - - - \\(adding\: equations\: 1 \:\&\:2) \\ ( \frac{1}{4} + \frac{3}{4} )x = \frac{5}{8} + 3 \frac{3}{8} \\ \\ \frac{4}{4} x = \frac{5}{8} + \frac{27}{8} \\ \\ x = \frac{32}{8} \\ \\ x = 4 \\ \\ plug \: x = 4 \: in \: equation \: (1) \\ \\ \frac{1}{\cancel 4} \times \cancel 4 + 1 \frac{1}{2} y = \frac{5}{8} \\ \\ 1 + \frac{3}{2} y = \frac{5}{8} \\ \\ \frac{3}{2} y = \frac{5}{8} - 1\\ \\ \frac{3}{2} y = \frac{5 - 8}{8}\\ \\ \frac{3}{2} y = \frac{ - 3}{8}\\ \\ y = \frac{ - 3}{8} \times \frac{2}{3} \\ \\ y = \frac{1}{4} \\ \\ (x, \: \: y) = (4, \: \: - \frac{1}{4} )[/tex]

Answer:

because all the numbers used are whole numbers and as a result will appear clearly on a graph. if there were decimals you would need to estimate and the answer would not be accurate

Answer:

the two triangles arent similar

Step-by-step explanation:

In order for the two triangles to be similar the sides GR and RA and SR and ST have to have the same ratio and they don't because 45/18 is 4.5 and 36/15 is 2.4.