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Alecsey [184]
2 years ago
8

Which of the following is a key element in the proof of the law of cosines?

Mathematics
2 answers:
Mariulka [41]2 years ago
4 0
The best and most correct answer among the choices provided by the question is the fourth choice "d=square root of (x^2+x^1)+(y^2-y^1)^2"
The law of cosines<span> for calculating one side of a triangle when the angle opposite and the other two sides are known. Can be used in conjunction with the </span>law<span> of sines to find all sides and angles. </span>

I hope my answer has come to your help. God bless and have a nice day ahead!
Vikentia [17]2 years ago
4 0

The <em><u>correct answer</u></em> is:

D) d=√((x+x¹)+(y²-y¹)² )

Explanation:

The distance formula is a key component to the proof of the law of cosines.

First we define sin θ = y/b and cos θ = x/b, using the standard law of cosines diagram.

We then use the distance formula, replacing the second y coordinate with 0 and the second x coordinate with a.

We then substitute our values for sin θ and cos θ, square them and simplify.

You might be interested in
Which of the following is a solution of the equation -5x + 2 = -13: answers: x=-9, x=75 x=3 x=-3
slamgirl [31]

Answer:

x= 3

Step-by-step explanation:

1. -5(3) + 2 = -13      

2. -15 + 2 = -13         <em>A positive times a negative will always equal a negative</em>

3. -13 = -13         <em>Whenever you add anything to a negative number, the                    </em>

<em>                            number becomes smaller   </em>

                     Ex:  -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, ...........

                           <em>Although the number itself becomes smaller, its value    </em>

<em>                             becomes bigger       </em>

Hope this helps.

7 0
3 years ago
What is another way to write the absolute value inequality lp|&lt;1 2?
PIT_PIT [208]

Answer:

|p| ≤ 12

Step-by-step explanation:

The absolute value of p less than or equal to 12

8 0
2 years ago
Find the solution to the inequality<br><br> 23(6x−3)&gt;6?
laiz [17]

Answer:

The answer is x>25/46

Step-by-step explanation:

Distribute 23 through the parentheses

138x-69>6

Move constant to the the right and change the sign. 138x>6+69.

Add the numbers like this: 138x>75

Divide both sides and you'll will get x>25/46 which is your answer. Let me know if this helps

8 0
2 years ago
What is f(-2) of the function given below? *<br> f(x) = 3x2 - 4x + 1
slava [35]

Answer:

f(-2) = 21

Step-by-step explanation:

Step 1: Define

f(x) = 3x² - 4x + 1

f(-2) is x = -2

Step 2: Substitute and Evaluate

f(-2) = 3(-2)² - 4(-2) + 1

f(-2) = 3(4) + 8 + 1

f(-2) = 12 + 9

f(-2) = 21

5 0
3 years ago
Given: cos θ=-4/5, sin x = -12/13, θ is in the third quadrant, 
USPshnik [31]

By definition of tangent,

tan(2<em>θ</em>) = sin(2<em>θ</em>) / cos(2<em>θ</em>)

Recall the double angle identities:

sin(2<em>θ</em>) = 2 sin(<em>θ</em>) cos(<em>θ</em>)

cos(2<em>θ</em>) = cos²(<em>θ</em>) - sin²(<em>θ</em>) = 2 cos²(<em>θ</em>) - 1

where the latter equality follows from the Pythagorean identity, cos²(<em>θ</em>) + sin²(<em>θ</em>) = 1. From this identity we can solve for the unknown value of sin(<em>θ</em>):

sin(<em>θ</em>) = ± √(1 - cos²(<em>θ</em>))

and the sign of sin(<em>θ</em>) is determined by the quadrant in which the angle terminates.

<em />

We're given that <em>θ</em> belongs to the third quadrant, for which both sin(<em>θ</em>) and cos(<em>θ</em>) are negative. So if cos(<em>θ</em>) = -4/5, we get

sin(<em>θ</em>) = - √(1 - (-4/5)²) = -3/5

Then

tan(2<em>θ</em>) = sin(2<em>θ</em>) / cos(2<em>θ</em>)

tan(2<em>θ</em>) = (2 sin(<em>θ</em>) cos(<em>θ</em>)) / (2 cos²(<em>θ</em>) - 1)

tan(2<em>θ</em>) = (2 (-3/5) (-4/5)) / (2 (-4/5)² - 1)

tan(2<em>θ</em>) = 24/7

4 0
3 years ago
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