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2 years ago

Help please

Mathematics

1 answer:

Levart [38]2 years ago

8 0

Answer:

-0.8 (A) -2.25 (B) -2 (C) (Look at explanation to see answers for first bubbles.)

Step-by-step explanation:

1.4 - 2.2 = -0.8

-0.75 - 1.5 = -2.25

-0.2 - 1.8 = -2

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Suppose cos(x)= -1/3, where π/2 ≤ x ≤ π. What is the value of tan(2x). EDGE

AVprozaik [17]

Answer:

Step-by-step explanation:

We are given that:

$\displaystyle \cos x = -\frac{1}{3}\text{ where } \pi /2 \leq x \leq \pi$

And we want to find the value of tan(2<em>x</em>).

Note that since <em>x</em> is between π/2 and π, it is in QII.

In QII, cosine and tangent are negative and only sine is positive.

We can rewrite our expression as:

$\displaystyle \tan(2x)=\frac{\sin(2x)}{\cos(2x)}$

Using double angle identities:

$\displaystyle \tan(2x)=\frac{2\sin x\cos x}{\cos^2 x-\sin^2 x}$

Since cosine relates the ratio of the adjacent side to the hypotenuse and we are given that cos(<em>x</em>) = -1/3, this means that our adjacent side is one and our hypotenuse is three (we can ignore the negative). Using this information, find the opposite side:

$\displaystyle o=\sqrt{3^2-1^2}=\sqrt{8}=2\sqrt{2}$

So, our adjacent side is 1, our opposite side is 2√2, and our hypotenuse is 3.

From the above information, substitute in appropriate values. And since <em>x</em> is in QII, cosine and tangent will be negative while sine will be positive. Hence:

<h2> $\displaystyle \tan(2x)=\frac{2(2\sqrt{2}/3)(-1/3)}{(-1/3)^2-(2\sqrt{2}/3)^2}$ </h2>

Simplify:

$\displaystyle \tan(2x)=\frac{-4\sqrt{2}/9}{(1/9)-(8/9)}$

Evaluate:

$\displaystyle \tan(2x)=\frac{-4\sqrt{2}/9}{-7/9} = \frac{4\sqrt{2}}{7}$

The final answer is positive, so we can eliminate A and B.

We can simplify D to:

$\displaystyle \frac{2\sqrt{8}}{7}=\frac{2(2\sqrt{2}}{7}=\frac{4\sqrt{2}}{7}$

So, our answer is D.

7 0

3 years ago

HELP I REALLY REALLY NEED THIS HELP MEE SUPER EZ 28 POINTS I REALLY NEED THIS I DONT REALLY CARE IF ITS WRONG AT LEAST YOU TRY ;

Lesechka [4]

Answer:

43. I'm not really sure about this one but here's what I got:

The average height of a 4th grader is 58 inches. (Maybe that'll help) Also if it's by the number of kids in the class....I would assume that there are at most 33 kids in the class....I'm not sure what it's asking...sorry :(

46. There are 8 total marbles so if you were selecting a green marble the probability of getting a green marble would be 3/8. If there are 2 blue marbles then the probability would be 2/8 or 1/4

LINK: https://mathbitsnotebook.com/Geometry/Probability/PBIndependentDependent.html

48. In a deck of cards there are 26 black cards and 26 red cards. Number of event occurrences. Total number of trials. For example, if a dice is rolled 6000 times and the number '5' occurs 990 times, then the experimental probability that '5' shows up on the dice is 990/6000 = 0.165. That should help with this one

LINK:

https://explorable.com/experimental-probability

49. Since there are 6 sides and each side is a number 1-6, the probability of rolling a six is 1:6

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3 years ago

What number has 8 hundreds, 2 fewer tens than hundreds and 2 fewer ones than hundreds

Aleonysh [2.5K]

3 hundred 1 fewer hundreds

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3 years ago

Write 14/25 as a decimal. Show work

Fudgin [204]

Answer:

14.25 decimal para saken

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2 years ago

Could someone help with my previously asked questions

m_a_m_a [10]

Answer:

ill try! <3

Step-by-step explanation:

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3 years ago

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