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2 years ago

Giải phương trình : 8cos 4 x – 4cos2x + sin4x – 4 = 0

Mathematics

1 answer:

alex41 [277]2 years ago

5 0

Answer:

Step-by-step explanation:

$8(1+cos2x/2)^{2} -4c0s2x+sin4x-4=0\\2(1+2cos2x+cos^{2}2x )-4cos2x+sin4x-4=0\\2cos^{2} 2x+sin4x-2=0\\1+cos4x+sin4x-2=0\\cos4x+sin4x=1\\sin(4x+\pi /4)=sin\frac{\pi }{4} \\\left \{ {{4x+\frac{\pi }{4} =\frac{\pi }{4}+k2\pi } \atop {4x+\frac{\pi }{4} =\frac{3\pi }{4} +k2\pi \\$

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WHAT IS THE VALUE IF X???‼️‼️ HELP ASAP

MaRussiya [10]

The value of x is 40.

Solution:

Given ΔVDG and ΔVNG are similar triangles.

DG = 207, NQ = 138, GQ = 60, QV = x

To find the value of x.

In two triangles are similar, then the measures of the corresponding sides are in proportional to each other.

$$\Rightarrow\frac{DG}{NQ}=\frac{GQ}{QV}$

Substitute the given values.

$$ \Rightarrow\frac{207}{138}=\frac{60}{x}$

Do cross multiplication, we get

$$ \Rightarrow{207\times x}=138\times60$

$$ \Rightarrow{207\times x}=8280$

Divide by 207 on both sides of the equation, we get

$$ \Rightarrow x=\frac{8280}{207}$

$$ \Rightarrow x=40$

Hence the value of x is 40.

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3 years ago

The equation 2x2 − 3x + 1 = 0 is in quadratic form. true or false

-BARSIC- [3]

Answer:

True

Step-by-step explanation:

The equation 2x² - 3x + 1 = 0 is in quadratic form.

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2 years ago

Read 2 more answers

What is the equation in point−slope form of the line passing through (−2, −5) and (2, 3)?

Sloan [31]

Hi,

m = (y-y₀)/(x-x₀)
m = (-5-3)/(-2-2)
m = -8/-4
m = 2

For point (2,3) ⇒ x₀ = 2 and y₀ = 3

y-y₀ = m(x-x₀)
y-3 = 2(x-2)

For point (-2,-5) ⇒ x = -2 and y = -5

-5-3 = 2(-2-2)
-8 = 2(-4)
-8 = -8 ⇒ True

Answer:

C. The equation is y-3 = 2(x-2)

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3 years ago

Why do you think the government charges high taxes on cigarettes?

Rom4ik [11]

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3 years ago

Bill's recipe for onion soup call for 4.0lb of thinly sliced onions. If an onion has an average mass of 115g, how many onions do

musickatia [10]

Answer:

1. $16\ onions$

2. $4,040.91\ kg$

Step-by-step explanation:

1. You know that the average mass of an onion is 115 grams and Bill needs 4.0 pounds.

Then, since $1\ lb=453.592\ g$ , we can make the following conversion:

$(4.0\ lb)(\frac{453.592\ g}{1\ lb})=1,814.37\ g$

Then, the number of onions Bill needs is:

$(1,814.37\ g)(\frac{1\ onion}{115\ g})=15.77\ onions$ ≈ $16\ onions$

2. Since $1\ kg=2.20462\ lb$ , we can make the following conversion:

$(11\ lb)(\frac{1\ kg}{2.20462\ lb})=4.98\ kg$

Knowing that all the potatoes sold today at the store bring in $1,420 and 4.98 kilograms of potatoes is $1.75, we can calculate the amount of kilograms the grocery shoppers bought:

$(\$1,420)(\frac{4.98\ kg}{\$1.75})=4,040.91\ kg$

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3 years ago