The value of cos 4x from the given identity is 0.999
<h3>Trigonometry identity</h3>
Given the cosine identity
cos8x = 13/36
Determine the value of x
8x = arccos(13/36)
8x = 0.36111
x = 0.36111/8
x = 0.04514
Determine the value of cos4x
cos4x = cos4(0.04514)
cos4(0.04514) = 0.999
Hence the value of cos 4x from the given identity is 0.999
Learn more trig identity here; brainly.com/question/7331447
Answer:
The probability that an elementary or secondary school teacher selected at random from this city is a female or holds a second job is 0.90.
Step-by-step explanation:
Denote the events as follows:
<em>X</em> = an elementary or secondary school teacher from a city is a female
<em>Y</em> = an elementary or secondary school teacher holds a second job
The information provided is:
P (X) = 0.66
P (Y) = 0.46
P (X ∩ Y) = 0.22
The addition rule of probability is:
Use this formula to compute the probability that an elementary or secondary school teacher selected at random from this city is a female or holds a second job as follows:
Thus, the probability that an elementary or secondary school teacher selected at random from this city is a female or holds a second job is 0.90.
Answer:
Klorina's rate in still water is 4.5 km/h
Current's rate is 0.5 km/h
Step-by-step explanation:
Let
x km/h = Klorina's rate in still water
y km/h = current's rate
<u>With the current (current helps):</u>
Distance = 10 km
Time = 2 hours
Rate = x + y km/h
<u>Against the current:</u>
Distance = 8 km
Time = 2 hours
Rate = x - y km/h
Divide both equations by 2:
Add these equations:
Subtract these two equations:
Answer:
- 50 ft by 75 ft
- 3750 square feet
Step-by-step explanation:
Let x represent the length of the side not parallel to the partition. Then the length of the side parallel to the partition is ...
y = (300 -2x)/3
And the enclosed area is ...
A = xy = x(300 -2x)/3 = (2/3)(x)(150 -x)
This is the equation of a parabola with x-intercepts at x=0 and x=150. The line of symmetry, hence the vertex, is located halfway between these values, at x=75.
The maximum area is enclosed when the dimensions are ...
50 ft by 75 ft
That maximum area is 3750 square feet.
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<em>Comment on the solution</em>
The generic solution to problems of this sort is that half the fence (cost) is used in each of the orthogonal directions. Here, half the fence is 150 ft, so the long side measures 150'/2 = 75', and the short side measures 150'/3 = 50'. This remains true regardless of the number of partitions, and regardless if part or all of one side is missing (e.g. bounded by a barn or river).
Answer:
8.49 × 10⁻³
Explanation:
Standard form of a number: A. × 10ᵇ
(where 'A' is the number, b is the exponent over 10)
For the number "0.00849", move the decimal point 3 places right so the exponent of 10 is -3.
Standard form: 8.49 × 10⁻³
Other examples of standard/scientific forms are: standard forms
i) 0.043, move the decimal point 2 places right = 4.3 × 10⁻²
ii) 4030, move the decimal point 3 places left = 4.03 × 10³
