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4 years ago

Evaluate for d = 2. 2(d + 4d)

Mathematics

2 answers:

Lunna [17]4 years ago

8 0

Answer: d = 12

2(2 + 4d)

Disturbte the 2 time everything and you get

4 + 8D add alike variable and the answer is d=12

Sav [38]4 years ago

6 0

Substitute 2 for d.

$2(d + 4d) \\ 2(2 + (4 \times 2)) \\ 2(2 + 8) \\ 2(10) \\ 20$

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3 years ago

What happens to the total mass of the atoms involved in a chemical reaction

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RainbowSalt2222 ☔

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3 years ago

Futhe Mathematics <img src="https://tex.z-dn.net/?f=%28Cos%20%7B%7D%5E%7B4%7Dt%20-Sin%20%7B%7D%5E%7B4%7Dt%20%29%20%20%5Cdiv%2

Nastasia [14]

Answer:

cos2t/cos²t

Step-by-step explanation:

Here the given trigonometric expression to us is ,

$\longrightarrow \dfrac{cos^4t - sin^4t }{cos^2t }$

We can write the numerator as ,

$\longrightarrow \dfrac{ (cos^2t)^2-(sin^2t)^2}{cos^2t }$

Recall the identity ,

$\longrightarrow (a-b)(a+b)=a^2-b^2$

Using this we have ,

$\longrightarrow \dfrac{(cos^2t + sin^2t)(cos^2t-sin^2t)}{cos^2t}$

Again , as we know that ,

$\longrightarrow sin^2\phi + cos^2\phi = 1$

Therefore we can rewrite it as ,

$\longrightarrow \dfrac{1(cos^2t - sin^2t)}{cos^2t}$

Again using the first identity mentioned above ,

$\longrightarrow \underline{\underline{\dfrac{(cost + sint )(cost - sint)}{cos^2t}}}$

Or else we can also write it using ,

$\longrightarrow cos2\phi = cos^2\phi - sin^2\phi$

Therefore ,

$\longrightarrow \underline{\underline{\dfrac{cos2t}{cos^2t}}}$

And we are done !

$\rule{200}{4}$

Additional info :-

Derivation of cos²x - sin²x = cos2x :-

We can rewrite cos 2x as ,

$\longrightarrow cos(x + x )$

As we know that ,

$\longrightarrow cos(y + z )= cosy.cosz - siny.sinz$

So that ,

$\longrightarrow cos(x+x) = cos(x).cos(x) - sin(x)sin(x)$

On simplifying,

$\longrightarrow cos(x+x) = cos^2x - sin^2x$

Hence,

$\longrightarrow\underline{\underline{cos (2x) = cos^2x - sin^2x }}$

$\rule{200}{4}$

7 0

3 years ago

The ages, in years, of children at a birthday party, are 4, 7, 8, 2, 9, 6, 5, 5, 9, 7, 8. What is the median age?

sveticcg [70]

Answer:

The median age is 7.

Step-by-step explanation:

2, 4, 5, 5, 6, 7, 7, 8, 8, 9, 9,

First you put the numbers in the right numerical order. Then you find the the middle/central number out of all the numbers in the numerical data set in order to find the median.

Hope you found this helpful! :)

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3 years ago