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VladimirAG [237]

3 years ago

13

Please help I really need to bring up my grades

1 answer:

natita [175]3 years ago

8 0

Answer:

a is 12- 7 = 5

Step-by-step explanation:

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Solve each inequality and graph the solutions , ILL MARK BRAINLIST !!!!

inn [45]

Answer:

see below

Step-by-step explanation:

2d+21 ≤11

Subtract 21

2d+21-21 ≤11 -21

2d ≤-10

Divide by 2

2d/2 ≤-10/2

d≤-5

4 0

4 years ago

Sin(4x) in the term of just x<br> Please help!!

Nina [5.8K]

I think you mean in terms of $\sin(x)$ ?

Recall Euler's identity

$e^{ix} = \cos(x) + i \sin(x)$

and de Moivre's theorem

$\left(e^{ix}\right)^n = \left(\cos(x) + i \sin(x)\right)^n = \cos(nx) + i \sin(nx) = e^{inx}$

where $i=\sqrt{-1}$ .

It follows that

$\sin(4x) = \mathrm{Im}\left(\cos(x) + i \sin(x)\right)^4$

By the binomial theorem, expanding the right side gives

$\cos^4(x) + 4i \cos^3(x) \sin(x) - 6\cos^2(x) \sin^2(x) - 4i \cos(x) \sin^3(x) + \sin^4(x)$

and so

$\sin(4x) = 4\cos^3(x) \sin(x) - 4 \cos(x) \sin^3(x)$

We can factorize this as

$\sin(4x) = 4 \cos(x) \sin(x) \left(\cos^2(x) - \sin^2(x)\right)$

and using the Pythagorean identity

$\cos^2(x)+\sin^2(x) = 1 \implies \cos(x) = \pm \sqrt{1-\sin^2(x)}$

this reduces to

$\sin(4x) = \pm 4 \sqrt{1-\sin^2(x)} \sin(x) (1 - 2 \sin^2(x))$

8 0

2 years ago

Help plss<br> this is due in an hour<br> i’ll give brainliest

scZoUnD [109]

Yss the answer is c

4 0

3 years ago

what is the solution to the system of equations? y = 2x – 3.5 x – 2y = –14 (–7, 3.5) (3.5, –7) (7, 10.5) (10.5, 7)

AnnyKZ [126]

we have the system of equations

$y=2x-3.5$ --------> equation $1$

$x-2y=-14$ --------> equation $2$

Multiply by $2$ equation $1$

$2y=4x-7$ --------> equation $3$

Adds equation $2$ and equation $3$

$x-2y=-14 \\ 2y=4x-7\\ --------\\ x=-14+4x-7\\ 4x-x=14+7\\ 3x=21\\ x=7$

Find the value of y

$y=2x-3.5$

$y=2*7-3.5$

$y=10.5$

the solution of the system is the point $(7,10.5)$

therefore

the answer is

$(7,10.5)$

8 0

4 years ago

Read 2 more answers

What is the value of 6 + 2x2, when x = 3?<br> X

Lyrx [107]

6 + 2(x)2
6 + 2(3)2
=6 + 6(2)
=6 + 12
=18

5 0

3 years ago

Read 2 more answers