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Margaret [11]
3 years ago
14

Find the exact value of the expression cos10°cos20°-sin10°sin20° Please Help

Mathematics
1 answer:
Svet_ta [14]3 years ago
5 0
Cos10 cos20 -sin10 sin20 = cos(10+20) = cos30 = √3/2
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Thirty percent of the students at a local high school face a disciplinary action of some kind before they graduate. Of those "fe
inna [77]

Answer:

Not independent

Step-by-step explanation:

For two events to be independent, they must not effect each other. For two independent events, changes in one of the event do not cause any change on the other event.

To explain it in terms of probability, let's first define and calculate the probabilities:

P(F) : Probability of facing felony

P(C) : Probability of going to college

P(F ∩ C) : Probability of facing felony and going to college

P(F° ∩ C): Probability of not facing a felony and going to college

Assume we have 100 students:

Faced felony = 0.3 * 100 = 30

Faced felony and go college = 30 * 0.4 = 12

Not faced felony = 0.7 * 100 = 70

Not faced felony and go college = 0.6 * 70 = 42

Total of going to college = 12 + 42 = 54

So P(C) = 54 / 100 = 0.54

If P(F)*P(C) = P(F ∩ C), then these two events are independent. If not, they are not independent.

Let's calculate the probabilities:

As given in the question, 30% of students face felony so P(F) = 0.3

P(C) = P(C ∩ F) + P(C ∩ F°) = 0.12 + 0.42 = 0.54

P(F) = 0.3

P(F ∩ C) = 0.12

P(F)*P(C) = 0.3 * 0.54 = 0.162 which ic not equal to P(F ∩ C). Therefore, these events are not independent.

5 0
3 years ago
Andell is 9 years older than Arnez. arnez is 3 years younger than Marianne. the sum of their ages is 24. what is the age of each
Harman [31]

Answer:

Arnez is 4. Andell is 13. Marianne is 7.

Step-by-step explanation:

Let x represent Arnez's age. If we write out an equation, we end up with this:

24 = (9 + x) + (x + 3) + x

24 = 9 + x + x + 3 + x

24 = (x + x + x) + (9 + 3)

24 = 3x + 12

24 - 12 = 3x + 12 - 12

12 / 3 = 3x / 3

4 = x

5 0
3 years ago
Ramon wants to make an acute triangle with three pieces of wood. So far, he has cut wood lengths of 7 inches and 3 inches. He st
o-na [289]

Answer: Exactly square root 58 inches

Step-by-step explanation: The dimensions given for the right angled triangle are 7 inches and 3 inches respectively. The third side is yet unknown. However what we know is that a right angled triangle can be solved by using the Pythagoras theorem which states that,

AC^2 = AB^2 + BC^2

Where AC is the longest side. The question requires us to calculate the longest side and with the other two sides already known, the Pythagoras theorem now becomes,

AC^2 = 7^2 + 3^2

AC^2 = 49 + 9

AC^2 = 58

Add the square root sign to both sides of the equation

AC = square root 58 inches

5 0
2 years ago
Read 2 more answers
Name all segments parallel to XT
butalik [34]

name two segments parallel to VU.

ST,ZY,WX

NAME TWO SEGMENTS SKEW TO SW VU,ZY,UT,XY

NAME TWO SEGMENTS SKEW TO XY SW,VZ,VS,ST,VU

8 0
3 years ago
Read 2 more answers
Th<br> Write an<br> explicit formula for<br> ans<br> then<br> term of the sequence 40,50,60, ....
kenny6666 [7]
<h3>Answer:   a_n = 10n+30</h3>

n starts at 1, and n is a positive whole number (1,2,3,...)

======================================================

Explanation:

The sequence is arithmetic with first term 40 and common difference 10. Meaning we add 10 to each term to get the next one.

--------

a1 = 40 = first term

d = 10 = common difference

a_n = a_1 + d(n-1)\\\\a_n = 40 + 10(n-1)\\\\a_n = 40 + 10n-10\\\\a_n = 10n + 30\\\\

is the general nth term of this arithmetic sequence

Plug in n = 1 and you should get a_1 = 40

Plug in n = 2 and you should get a_2 = 50

and so on

6 0
3 years ago
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