Answer:
simply convert first feets into miles
Given is 5280 feets=1 miles
63756 /5280=12.075 miles
70 minutes = 1.16666= 1.17 hrs
rate is 12.075 miles/1.17 hrs
Step-by-step explanation:
Simplify to create an equivalent expression.
\qquad{7n-(4n-3)}7n−(4n−3)
Answer:
[tex]3n + 3[/tex]
[tex]3(n+1)[/tex]
Step-by-step explanation:
Given
[tex]7n - (4n - 3)[/tex]
Required
Simplify
To simplify the given expression, you start by opening the bracket
[tex]7n - (4n - 3)[/tex]
[tex]7n - 4n + 3[/tex]
Next, you perform arithmetic operations on like terms
[tex]3n + 3[/tex]
The answer can be further simplified;
Factorize [tex]3n + 3[/tex]
[tex]3(n+1)[/tex]
Hence;
[tex]7n - (4n - 3)[/tex] when simplified is equivalent to [tex]3n + 3[/tex] or [tex]3(n+1)[/tex]
Answer:
3n+n
Step-by-step explanation:
Hi i need help on this im not that smart sorry, what is the x-intercept of the graph that is shown below
Answer:
(3, 0)
Step-by-step explanation:
x-intercept is where the line touches the x-axis
It is the point on the line where y=0
Answer:
3,0
Step-by-step explanation:
the point where the line cuts the x axis is the x-intecept
find out what's wrong with this graph
Answer:
The y-axis is upside down, meaning that instead of the values increasing as they go up, they decrease.
The top speed of this coaster is
128 mph. What is the tallest peak
of this coaster?
** Hint... convert mph into m/s.*
To convert miles per hour to meters per second divide by 2.237
128 miles per hour / 2.237 = 57.22 meters per second.
Using the first equation:
57.22 = sqrt(2 x 9.81 x h)
Remove the sqrt by raising both sides to the second power:
57.22^2 = (2 x 9.81 x h)
Simplify Both sides:
3274.1284 = 19.62h
Divide both sides by 19.62:
H = 3274.1284/ 19.62
H = 166.88 meters
When you enter the Texas Turnpike, they give you a ticket showing the time and place of your entry. When you exit, you turn in this ticket and they use it to figure your toll. Because they know the distance between toll stations, they can also use it to check your average speed against the turnpike limit of 65 mph. On your trip, heavy snow limits your speed to 40 mph for the first 120 mi. At what average speed can you drive for the remaining 300 mi without having your ticket prove that you broke the speed limit?
Answer:
87 mph
Step-by-step explanation:
Total distance needed is 120 mi + 300 mi and that is 420 mi.
Driving at 65 mph means that it would take
420 / 65 hours to reach his destination.
6.46 hours .
at the first phase, he drove at 40 mph for 120 mi, this means that it took him
120 / 40 hours to complete the journey.
3 hours.
the total time needed for the whole journey is 6.46 hours, and he already spent 3 hours in the first phase. To keep up with the 6.46 hours required, in the second phase, he has to drive at a speed of
6.46 - 3 hours = 3.46 hours.
300 mi / 3.46 hours => 86.71 mph approximately 87 mph
Therefore, he needs to drive at not more than 87 mph to keep up with the journey while not breaking his speed limit
Find the measure of ∠BEF
Please HELP ASAP
Answer:
100°
Step-by-step explanation:
We know that angles EFD and AEF are the same as they are alternate interior angles.
We also can note that BEF and AEF are supplementary, meaning their angle lengths will add up to 180°.
So we can create an equation:
(2x + 60) + (3x + 20) = 180
Combine like terms:
5x + 80 = 180
Subtract 80 from both sides
5x = 100
Divide both sides by 5
x = 20.
Now we can use this to find the measure of BEF.
[tex]2\cdot20 + 60[/tex]
[tex]40 + 60 = 100[/tex]
Hope this helped!
Answer:
BEF = 100
Step-by-step explanation:
The angles are same side interior angles and same side interior angles add to 180 degrees
2x+60 + 3x+20 = 180
Combine like terms
5x+80 = 180
Subtract 80
5x = 100
Divide by 5
5x/5 = 100/5
x = 20
We want BEF
BEF = 2x+60
= 2x+60
= 2*20 +60
= 40+60
= 100
8.What side of the road will you see speed, yield, and guide signs on ?
Answer:
we see it in our left side of the road
what is the domain of f(x)=(1/4)^x
Answer:
B All real numbers
hope you wil understand
Answer:
[tex]\boxed{\sf B. \ All \ real \ numbers}[/tex]
Step-by-step explanation:
The domain is all possible values for x.
[tex]f(x)=(\frac{1}{4} )^x[/tex]
There are no restrictions on the value of x.
The domain is all real numbers.
The general manager, marketing director, and 3 other employees of CompanyAare hosting a visitby the vice president and 2 other employees of CompanyB. The eight people line up in a randomorder to take a photo. Every way of lining up the people is equally likely.Required:a. What is the probability that the bride is next to the groom?b. What is the probability that the maid of honor is in the leftmost position?c. Determine whether the two events are independent. Prove your answer by showing that one of the conditions for independence is either true or false.
Answer:
Following are the answer to this question:
Step-by-step explanation:
Let, In the Bth place there are 8 values.
In point a:
There is no case, where it generally manages its next groom is = 7 and it will be arranged in the 2, that can be arranged in 2! ways. So, the total number of ways are: [tex]\to 7 \times 2= 14\\\\ \{(1,2),(2,1),(2,3),(3,2),(3,4),(4,3),(4,5),(5,4),(5,6),(6,5),(6,7),(7,8),(8,7),(7,6)\}\\[/tex][tex]\therefore[/tex] required probability:
[tex]= \frac{14}{8!}\\\\= \frac{14}{8\times7 \times6 \times 5 \times 4 \times 3\times 2 \times 1 }\\\\= \frac{1}{8\times6 \times5 \times 4 \times 3}\\\\= \frac{1}{8\times6 \times5 \times 4 \times 3}\\\\=\frac{1}{2880}\\\\=0.00034[/tex]
In point b:
Calculating the leftmost position:
[tex]\to \frac{7!}{8!}\\\\\to \frac{7!}{8 \times 7!}\\\\\to \frac{1}{8}\\\\\to 0.125[/tex]
In point c:
This option is false because
[tex]\to P(A \cap B) \neq P(A) \times P(B)\\\\\to \frac{12}{8!} \neq \frac{14}{8!}\times \frac{1}{8}\\\\\to \frac{12}{8!} \neq \frac{7}{8!}\times \frac{1}{4}\\\\[/tex]
A thin metal plate, located in the xy-plane, has temperature T(x, y) at the point (x, y). Sketch some level curves (isothermals) if the temperature function is given by
T(x, y)= 100/1+x^2+2y^2
Answer:
Step-by-step explanation:
Given that:
[tex]T(x,y) = \dfrac{100}{1+x^2+y^2}[/tex]
This implies that the level curves of a function(f) of two variables relates with the curves with equation f(x,y) = c
here c is the constant.
[tex]c = \dfrac{100}{1+x^2+2y^2} \ \ \--- (1)[/tex]
By cross multiply
[tex]c({1+x^2+2y^2}) = 100[/tex]
[tex]1+x^2+2y^2 = \dfrac{100}{c}[/tex]
[tex]x^2+2y^2 = \dfrac{100}{c} - 1 \ \ -- (2)[/tex]
From (2); let assume that the values of c > 0 likewise c < 100, then the interval can be expressed as 0 < c <100.
Now,
[tex]\dfrac{(x)^2}{\dfrac{100}{c}-1 } + \dfrac{(y)^2}{\dfrac{50}{c}-\dfrac{1}{2} }=1[/tex]
This is the equation for the family of the eclipses centred at (0,0) is :
[tex]\dfrac{x^2}{a^2}+\dfrac{y^2}{b^2}=1[/tex]
[tex]a^2 = \dfrac{100}{c} -1 \ \ and \ \ b^2 = \dfrac{50}{c}- \dfrac{1}{2}[/tex]
Therefore; the level of the curves are all the eclipses with the major axis:
[tex]a = \sqrt{\dfrac{100 }{c}-1}[/tex] and a minor axis [tex]b = \sqrt{\dfrac{50 }{c}-\dfrac{1}{2}}[/tex] which satisfies the values for which 0< c < 100.
The sketch of the level curves can be see in the attached image below.
Find the length of GV¯¯¯¯¯¯¯¯ A. 43.92 B. 33.1 C. 41.45 D. 68.87
Answer:
The answer is option AStep-by-step explanation:
Since the figure above is a right angled triangle we can use trigonometric ratios to find GV
To find GV we use cosine
cos∅ = adjacent / hypotenuse
From the question
GV is the adjacent
GC is the hypotenuse
So we have
[tex] \cos(37) = \frac{GV}{GC} [/tex]GC = 55°
GV[tex] \cos(37) = \frac{GV}{55} [/tex]GV = 55 cos 37
GV = 43.92495
We have the final answer as
GV = 43.92Hope this helps you
-8 + (-15)
Evaluate this expression
Answer:
-23
Step-by-step explanation:
-8+(-15) means that you are subtracting 15 from -8. So you end up with -8-15=-23.
When a constant force acts upon an object, the acceleration of the object varies inversely with its mass. When a certain constant force acts upon an object with mass 4kg, the acceleration of the object is 15/ms2. If the same force acts upon another object whose mass is
10kg, what is this object's acceleration?
Answer:
[tex]a = 6m/s^2[/tex]
Step-by-step explanation:
Given
When mass = 4kg; Acceleration = 15m/s²
Required
Determine the acceleration when mass = 10kg, provided force is constant;
Represent mass with m and acceleration with a
The question says there's an inverse variation between acceleration and mass; This is represented as thus;
[tex]a\ \alpha\ \frac{1}{m}[/tex]
Convert variation to equality
[tex]a = \frac{F}{m}[/tex]; Where F is the constant of variation (Force)
Make F the subject of formula;
[tex]F = ma[/tex]
When mass = 4kg; Acceleration = 15m/s²
[tex]F = 4 * 15[/tex]
[tex]F = 60N[/tex]
When mass = 10kg; Substitute 60 for Force
[tex]F = ma[/tex]
[tex]60 = 10 * a[/tex]
[tex]60 = 10a[/tex]
Divide both sides by 10
[tex]\frac{60}{10} = \frac{10a}{10}[/tex]
[tex]a = 6m/s^2[/tex]
Hence, the acceleration is [tex]a = 6m/s^2[/tex]
Are we adding all 4 sides ?
Answer:
Yes
Step-by-step explanation:
you would do 2(5x-10) + 2(8x+4)= 26x-12
Answer:
26x - 12
Step-by-step explanation:
The perimeter is the sum of all the exterior sides of a figure.
Here, we have a parallelogram, and its sides are 5x - 10, 8x + 4, 5x - 10, and 8x + 4. Adding these, we get:
(5x - 10) + (8x + 4) + (5x - 10) + (8x + 4) = 26x - 12
Thus, the answer is 26x - 12. Note that since the problem doesn't give a value for x, this cannot be simplified further.
~ an aesthetics lover
can anyone show me this in verbal form?
Answer:
2 * (x + 2) = 50
Step-by-step explanation:
Let's call the unknown number x. "A number and 2" means that we need to add the numbers, therefore it would be x + 2. "Twice" means 2 times a quantity so "twice a number and 2" would be 2 * (x + 2). "Is" denotes that we need to use the "=" sign and because 50 comes after "is", we know that 50 goes on the right side of the "=" so the final answer is 2 * (x + 2) = 50.
There are 30 colored marbles inside a bag. Six marbles are yellow, 9 are red, 7 are white, and 8 are blue. One is drawn at random. Which color is most likely to be chosen? A. white B. red C. blue D. yellow Include ALL work please!
Answer:
red
Step-by-step explanation:
Since the bag contains more red marbles than any other color, you are most likely to pick a red marble
What are the solutions of the equation x4 + 6x2 + 5 = 0? Use u substitution to solve.
x = i and x = i5
x=+ i and x
x= +115
O x=V-1 and x = = -5
x=+ -1 and x = = -5
Answer:
A; The first choice.
Step-by-step explanation:
We have the equation [tex]x^4+6x^2+5=0[/tex] and we want to solve using u-substitution.
When solving by u-substitution, we essentially want to turn our equation into quadratic form.
So, let [tex]u=x^2[/tex]. We can rewrite our equation as:
[tex](x^2)^2+6(x^2)+5=0[/tex]
Substitute:
[tex]u^2+6u+5=0[/tex]
Solve. We can factor:
[tex](u+5)(u+1)=0[/tex]
Zero Product Property:
[tex]u+5=0\text{ and } u+1=0[/tex]
Solve for each case:
[tex]u=-5\text{ and } u=-1[/tex]
Substitute back u:
[tex]x^2=-5\text{ and } x^2=-1[/tex]
Take the square root of both sides for each case. Since we are taking an even root, we need plus-minus. Thus:
[tex]x=\pm\sqrt{-5}\text{ and } x=\pm\sqrt{-1}[/tex]
Simplify:
[tex]x=\pm i\sqrt{5}\text{ and } x=\pm i[/tex]
Our answer is A.
Given the number of trials and the probability of success, determine the probability indicated: a. n = 15, p = 0.4, find P(4 successes) b. n = 12, p = 0.2, find P(2 failures) c. n = 20, p = 0.05, find P(at least 3 successes)
Answer:
A)0.126775 B)0.000004325376 C) 0.07548
Step-by-step explanation:
Given the following :
A.) a. n = 15, p = 0.4, find P(4 successes)
a = number of trials p=probability of success
P(4 successes) = P(x = 4)
USING:
nCx * p^x * (1-p)^(n-x)
15C4 * 0.4^4 * (1-0.4)^(15-4)
1365 * 0.0256 * 0.00362797056
= 0.126775
B)
b. n = 12, p = 0.2, find P(2 failures),
P(2 failures) = P(12 - 2) = p(10 success)
USING:
nCx * p^x * (1-p)^(n-x)
12C10 * 0.2^10 * (1-0.2)^(12-10)
66 * 0.0000001024 * 0.64
= 0.000004325376
C) n = 20, p = 0.05, find P(at least 3 successes)
P(X≥ 3) = p(3) + p(4) + p(5) +.... p(20)
To avoid complicated calculations, we can use the online binomial probability distribution calculator :
P(X≥ 3) = 0.07548
23. f(x) is vertically shrank by a factor of 1/3. How will you represent f(x) after transformation?
A. f(3x)
B. 3f(x)
C. 13f(x)
D. f(13x)
Answer:
Step-by-step explanation:
vertical stretching / shrinking has the following transformation.
f(x) -> a * f(x)
when a > 1, it is stretching
when 0< a < 1, it is shrinking.
when -1 < a < 0, it is shringking + reflection about the x-axis
when a < -1, it is stretching + reflection about the x axis.
Here it is simple shrinking, so 0 < a < 1.
I expect the answer choice to show (1/3) f(x).
However, if the question plays with the words
"shrink by a factor of 1/3" to actually mean a "stretching by a factor of three", then B is the answer (stretch by a factor of three).
what must be added to 2/3 of 5.25 to make it 7.00
Answer:
3.5
Step-by-step explanation:
Well you have to find first 2/3 of 5.25. This means multiplication, which is 3.5. so to find how much to add to this to get 7, we have to subtract 3.5 from 7. 7-3.5=3.5. so we must add 3.5 to get 7. Hope this helps :D
PLS HELPPPPPPPPPPP :p 8*10^3 is how many times larger that 4*10^2?
Answer:
20 times.
Step-by-step explanation:
To find out how many times larger a number is than another number, simply divide the two numbers, with the larger number being in the numerator.
For example, how many times larger is 6 than 2? The answer would be 6/2 or 3 times larger.
So, divide 8*(10^3) and 4*(10^2):
[tex]\frac{8\times10^3}{4\times10^2}[/tex]
Expand the expressions. This is the same as saying:
[tex]\frac{8\times10\times10\times10}{4\times10\times10}[/tex]
We can cancel two of the 10s since they are in both the numerator and the denominator. Thus, only one 10 is left in the numerator:
[tex]\frac{8\times10}{4}[/tex]
Simplify:
[tex]=\frac{80}{4} =20[/tex]
Therefore, 8*(10^3) (or 8000) is 20 times larger than 4*(10^2) (or 400).
Answer:
20 times
Step-by-step explanation:
hey,
so lets solve 8*10^3 first
so we use the order of operations
P
= Parentheses first
E
= Exponents (ie Powers and Square Roots, etc.)
MD
= Multiplication and Division (left-to-right)
AS
= Addition and Subtraction (left-to-right)
so after doing the exponents part 8*1000
we do the multiplication
=8000
SO THE FIRST NUMBER IS 8000
now lets solve 4*10^2
so we use the order of operations
P
= Parentheses first
E
= Exponents (ie Powers and Square Roots, etc.)
MD
= Multiplication and Division (left-to-right)
AS
= Addition and Subtraction (left-to-right)
so we do exponents first 4*100
then multiplication
=400
SO THE SECOND NUMBER IS 400
To find out how many times larger a number is than another number, simply divide the two numbers, with the larger number being in the numerator.
now we divide 8000 by 400
=20
so 8*10^3 is 20 times larger than 4*10^2
HOPE I HELPED
PLS MARK BRAINLIEST
DESPERATELY TRYING TO LEVEL UP
✌ -ZYLYNN JADE ARDENNE
JUST A RANDOM GIRL WANTING TO HELP PEOPLE!
PEACE!
A restaurant hands out a scratch-off game ticket with prizes being worth purchases at the restaurant. The back of the ticket lists the odds of winning each dollar value: 0.05 for $10, 0.04 for $25, 0.01 for $50, and 0.003 for $100. What are the odds that the ticket is worth at least $25?
Answer: 0.05412
Step-by-step explanation:
Formula : Odds of having an event is given by [tex]o=\dfrac{p}{1-p}[/tex], where p = probability that event happens.
In terms to find p , we use [tex]p=\dfrac{o}{1+o}[/tex]
Given, he back of the ticket lists the odds of winning each dollar value: 0.05 for $10, 0.04 for $25, 0.01 for $50, and 0.003 for $100.
Let X be the worth of ticket.
Then, the probability that the ticket is worth at least $25 =
[tex]P(X\geq 25)=P(X=25)+P(X=50)+P(X=100)[/tex]
[tex]=\dfrac{0.04}{1+0.04}+\dfrac{0.01}{1+0.01}+\dfrac{0.003}{1+0.003}\\\\=0.05135[/tex]
The odds that the ticket is worth at least $25 = [tex]\dfrac{0.05135}{1-0.05135}[/tex]
=0.05412
hence, the odds that the ticket is worth at least $25 is 0.05412 .
If the sample size is increased and the standard deviation and confidence level stay the same, then the margin of error will also be increased.
a. True
b. False
False!
The answer is: False.
Whomever stated the answer is "true" is wrong.
make a box-and-whisker plot for the data. numbers of colors in a country's flag :3,2,2,4,4,3,6,3,5,3,4,1
Answer: see attachment
Step-by-step explanation:
Put the numbers in order from smallest to biggest:
1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 5, 6
↓ ∨ ↓
Q1 Median Q3
Q1 median = (2+3)/2 = 2.5 <---- left side of box plot
Median = (3+3)/2 = 3 <---- Vertical Line of box plot
Q3 median = (4+4)/2 = 4 <---- right side of box plot
Consider the age distribution in the United States in the year 2075 (as projected by the Census Bureau). Construct a cumulative frequency plot and describe what information the plot communicates about the distribution of ages in the future.
Answer:
The cumulative frequency plot is also attached below.
Step-by-step explanation:
The data provided is as follows:
Age Group Frequency
0 - 9 34.9
10 - 19 35.7
20 - 29 36.8
30 - 39 38.1
40 - 49 37.8
50 - 59 37.8
60 - 69 34.5
70 - 79 27.2
80 - 89 18.8
90 - 99 7.7
100 - 109 1.7
Consider the Excel output attached.
The cumulative frequency are computed in the Excel sheet.
The cumulative frequency plot is also attached below.
From the cumulative frequency plot it can be seen that in the future most people will belong to a higher age group rather then the lower ones.
Chen is bringing fruit and veggies to serve at an afternoon meeting. He spends a total of $28.70 on 5 pints of cut veggies and 7 pints of cut fruit. The food cost is modeled by the equation 5 v plus 7 f equals 28.70, where v represents the cost of one pint of cut veggies and f represents the cost of one pint of cut fruit. If the cost of each pint of fruit is $2.85, what is the approximate price of a pint of veggies?
Answer:
(7 x 2.85) + 5v = 28.70. 19.95 + 5v = 28.70. 5v = 28.70 - 19.95. 5v = 8.75. v = 8.75/5. v = 1.75. A pint of veggies costs $1.75.
Find the value of x show your work
Answer:
x≈13.08
Step-by-step explanation:
We use the pythagora's theorem
[tex]a^{2} +b^2=c^2\\a=5\\b=x\\c=14\\5^2+x^2=14^2\\x^2=196-25\\x^2=171\\x=3\sqrt{19} =13.08[/tex]
sasha has some pennies nickels and dimes in her pocket. the number of coins is 18 the expression is 0.01p+0.05n+0.10d represents the value of the coins which is 1.08 she has twice as many dimes as pennies. How many of each coin does Sasha have
Answer:
3 pennies, 9 nickels, and 6 dimes
Step-by-step explanation:
We have three conditions:
(1) p + n + d = 18
(2) 0.01p + 0.05n + 0.10d = 1.08
(3) d = 2p
Multiply (2) by 100 and rearrange (3) to get a standard array.
(4) p + n + d = 18
(5) p + 5n + 10d = 108
(6) -2p + d = 0
Subtract (4) from (5). This gives
(4) p + n + d = 18
(7) 4n + 9d = 90
(6) -2p + d = 0
Multiply (4) by 2 and add to (6). This gives
(4) p + n + d = 18
(7) 4n + 9d = 90
(8) 2n + 3d = 36
Double (8) and subtract from (7). This gives
(4) p + n + d = 18
(7) 4n + 9d = 90
(9) 3d = 18
Divide (9) by 3. This gives
(10) d = 6
Substitute (10) into (7). This gives
4n + 9(6) = 90
4n + 54 = 90
4n = 36
(11) n = 9
Substitute (10) and (11) into (4). This gives
p + 9 + 6 = 18
p + 15 = 18
p = 3
Sasha has 3 pennies, 9 nickels, and 6 dimes.
Given a right triangle with a hypotenuse of 6 cm and a leg of 4cm, what is the measure of the other leg of the triangle rounded to the tenths?
Answer:
4.5 cm
Step-by-step explanation:
a^2+b^2=c^2
A represents the leg we already know, which has a length of 4 cm. C represents the hypotenuse with a length of 6 cm:
4^2+b^2=6^2, simplified: 16+b^2=36
subtract 16 from both sides:
b^2=20
now find the square root of both sides and that is the length of the other leg.
sqrt20= 4.4721, which can be rounded to 4.5
Answer:
4.5 cm
Step-by-step explanation:
Since this is a right triangle, we can use the Pythagorean Theorem.
[tex]a^2+b^2=c^2[/tex]
where a and b are the legs and c is the hypotenuse.
One leg is unknown and the other is 4 cm. The hypotenuse is 6 cm.
[tex]a=a\\b=4\\c=6[/tex]
Substitute the values into the theorem.
[tex]a^2+4^2=6^2[/tex]
Evaluate the exponents first.
4^2= 4*4= 16
[tex]a^2+16=6^2[/tex]
6^2=6*6=36
[tex]a^2+16=36[/tex]
We want to find a, therefore we must get a by itself.
16 is being added on to a^2. The inverse of addition is subtraction. Subtract 16 from both sides of the equation.
[tex]a^2+16-16=36-16\\\\a^2=36-16\\\\a^2=20[/tex]
a is being squared. The inverse of a square is a square root. Take the square root of both sides.
[tex]\sqrt{a^2}=\sqrt{20} \\\\a=\sqrt{20} \\\\a=4.47213595[/tex]
Round to the nearest tenth. The 7 in the hundredth place tells us to round the 4 in the tenth place to a 5.
[tex]a=4.5[/tex]
Add appropriate units. In this case, centimeters.
a= 4.5 cm
The length of the other leg is about 4.5 centimeters.
Express the product of z1 and z2 in standard form given that [tex]z_{1} = 6[cos(\frac{2\pi }{5}) + isin(\frac{2\pi }{5})][/tex] and [tex]z_{2} = 2\sqrt{2} [cos(\frac{-\pi }{2}) + isin(\frac{-\pi }{2})][/tex]
Answer:
Solution : 5.244 - 16.140i
Step-by-step explanation:
If we want to express the two as a product, we would have the following expression.
[tex]-6\left[\cos \left(\frac{2\pi }{5}\right)+i\sin \left(\frac{2\pi }{5}\right)\right]\cdot 2\sqrt{2}\left[\cos \left(\frac{-\pi }{2}\right)+i\sin \left(\frac{-\pi \:}{2}\right)\right][/tex]
Now we have two trivial identities that we can apply here,
( 1 ) cos(- π / 2) = 0,
( 2 ) sin(- π / 2) = - 1
Substituting them,
= [tex]-6\cdot \:2\sqrt{2}\left(0-i\right)\left(\cos \left(\frac{2\pi }{5}\right)+i\sin \left(\frac{2\pi }{5}\right)\right)[/tex]
= [tex]-12\sqrt{2}\sin \left(\frac{2\pi }{5}\right)+12\sqrt{2}\cos \left(\frac{2\pi }{5}\right)i[/tex]
Again we have another two identities we can apply,
( 1 ) sin(x) = cos(π / 2 - x )
( 2 ) cos(x) = sin(π / 2 - x )
[tex]\sin \left(\frac{2\pi }{5}\right)=\cos \left(\frac{\pi }{2}-\frac{2\pi }{5}\right) = \frac{\sqrt{2}\sqrt{5+\sqrt{5}}}{4}[/tex]
[tex]\cos \left(\frac{2\pi }{5}\right)=\sin \left(\frac{\pi }{2}-\frac{2\pi }{5}\right) = \frac{\sqrt{2}\sqrt{3-\sqrt{5}}}{4}[/tex]
Substitute,
[tex]-12\sqrt{2}(\frac{\sqrt{2}\sqrt{5+\sqrt{5}}}{4}) + 12\sqrt{2}(\frac{\sqrt{2}\sqrt{3-\sqrt{5}}}{4})[/tex]
= [tex]-6\sqrt{5+\sqrt{5}}+6\sqrt{3-\sqrt{5}} i[/tex]
= [tex]-16.13996 + 5.24419i[/tex]
= [tex]5.24419i - 16.13996[/tex]
As you can see option d is the correct answer. 5.24419 is rounded to 5.244, and 16.13996 is rounded to 16.14.
