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anzhelika [568]
3 years ago
9

Use the law of cosines to find the value of cos theta. round your answer to two decimal places

Mathematics
1 answer:
REY [17]3 years ago
7 0

<u>Answer:</u>

The correct answer option is B. 0.21.

<u>Step-by-step explanation:</u>

We are to find the value of cos \theta using the law of cosines.

We know that the formula of the cosine rule is given by:

c ^ 2 = a ^ 2 + b ^ 2 - 2 a b cos C

So substituting the given values in the above formula:

10.9 ^ 2 = 5.8 ^ 2 + 10.5 ^ 2 - 2 (5.8) (10.5) cos C

118.81=33.64+110.25-121.8cosC

118.81 - (33.64+110.25) = -121.8cosC

118.81-143.86=-121.8cosC

cosC=\frac{-25.05}{-121.8}

cos C = 0.21

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HELP please.
Scorpion4ik [409]

Answer:

C

Step-by-step explanation:

Here, originally, we are told that the point Q has coordinates (-2,1)

Now, its dilated point has the coordinates (-8,4)

what we can observe here is the the shape original polygon was dilated by a factor of 4 to give the image

Now the point R’ is (0,8)

To get the point R , we simply divide each coordinate by 4

Thus, we have (0/4 , 8/4)

This is same as option C

4 0
3 years ago
If M is the midpoint of LN = 27.8 , find the length of MN
Mars2501 [29]
Midpoint is almost like half. 

So, I am assuming that LN is one line and M represents the point that can divide L and N evenly.

27.8 / 2

13.9 = half of the line. 

Since MN would be the center to the end of one line, it would equal 13.9.

Have a nice day!
7 0
4 years ago
Mr.Henry expected 10 of the students in his Drama class to attend the school play.Instead,15 students in his class attended.What
katovenus [111]

Answer:50%

Step-by-step explanation: The correct way to calculate what percentage more attended the play is to first subtract the expected number from the actual number. 15 - 10 = 5 more attended than was expected. Next, you need to divide the 5 additional people by the 10 that were originally expected. 5 divided by 10 = 50%

4 0
3 years ago
Find the missing length indicated. x=
guapka [62]

Answer: x = 120

Step-by-step explanation:

Here we have 3 triangles, one big and two smaller ones, one at the left and other at the right.

Now, the right sides is shared by the right smaller triangle and the big triangle, if this length is Z, we have that (using the angle in top of it, A, such that 64 is adjacent to A.)

Cos(A) = 64/Z

Cos(A) = Z/(64 +225)

We can take the quotient of those two equations and get:

1 = \frac{64*(64 + 225)}{Z^2} = \frac{18496}{Z^2}

Then:

Z = √(18,496) = 136.

now, we have that for the smaller triangle one cathetus is equal to 64 and the hypotenuse is equal to 136.

Then, using the Pythagorean theorem:

64^2 + x^2 = 136^2

x = √(136^2 - 64^2) = 120

5 0
3 years ago
What is the surface area of the above composite object made out of two rectangular prisms?
aleksandrvk [35]

Answer:

  550 mm^2

Step-by-step explanation:

A net can be drawn as shown in the first figure attached. Each square represents 5 mm by 5 mm, so is 25 mm^2. Altogether, there are 22 of them, so the total area is ...

  (25 mm^2)·22 = 550 mm^2

The second attachment shows that net folded up to make the given figure.

_____

In the first attachment, the green shades represent the left- and right-side faces. (Darker green is left side.) The red and blue shades represent the front- and back-side faces. The white rectangles represent the top and bottom faces. The dark black lines are the cut lines. If you want to fold the figure up, the lighter lines are the fold lines.

The second attachment is just verification that all faces are accounted for and the net actually corresponds to the given figure.

4 0
3 years ago
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