Answers
2cos pi/13 cos 9pi/13+ cos 3pi/13 +cos 5pi/13
=cos 10 pi/13 +cos 8 pi/13 +cos 3pi/13 +cos 5pi/13
=cos 10 pi/13 +cos 3pi/13 +cos 8pi/13 +cos 5pi/13
=2 cos pi/2 .cos 7 pi/26 +2 cos pi/2 .cos 3 pi /26
=2 (0)cos 7 pi /26 + 2(0) cos 3pi/26
=0 =R.H.S.
Answer: see proof below
Step-by-step explanation:
Use the following identities:
2cos x · cos y = cos(x + y) + cos(x - y)
cos x + cos y = 2 cos (x + y)/2 · cos(x - y)/2
Use the Unit Circle to evaluate: cos(π/2) = 0
Proof LHS → RHS
[tex]\text{LHS:}\qquad \qquad \qquad 2\cos \dfrac{9\pi}{13}\cos \dfrac{\pi}{13}\quad +\quad \cos \dfrac{3\pi}{13}+\cos \dfrac{5\pi}{13}\\\\\text{Identity:}\qquad \quad \cos\bigg(\dfrac{9\pi}{13}+\dfrac{\pi}{13}\bigg)+ \cos\bigg(\dfrac{9\pi}{13}-\dfrac{\pi}{13}\bigg)+\quad \cos\bigg(\dfrac{3\pi}{13}\bigg)+\cos \bigg(\dfrac{5\pi}{13}\bigg)[/tex]
[tex]\text{Simplify:}\qquad \qquad \cos\bigg( \dfrac{10\pi}{13}\bigg)+\cos \bigg(\dfrac{8\pi}{13}\bigg)+\qquad \cos\bigg(\dfrac{3\pi}{13}\bigg)+\cos \bigg(\dfrac{5\pi}{13}\bigg)[/tex]
[tex]\text{Regroup:}\qquad \qquad \cos\bigg( \dfrac{10\pi}{13}\bigg)+\cos \bigg(\dfrac{3\pi}{13}\bigg)\quad +\quad \cos\bigg(\dfrac{8\pi}{13}\bigg)+\cos \bigg(\dfrac{5\pi}{13}\bigg)[/tex]
[tex]\text{Identity:}\qquad 2\cos \bigg(\dfrac{10\pi+3\pi}{13\cdot 2}\bigg)\cdot \cos \bigg(\dfrac{10\pi-3\pi}{13\cdot 2}\bigg)+\quad 2\cos\bigg(\dfrac{8\pi+5\pi}{13\cdot 2}\bigg)\cdot \cos\bigg(\dfrac{8\pi-5\pi}{13\cdot 2}\bigg)[/tex]
[tex]\text{Simplify:}\qquad 2\cos \bigg(\dfrac{13\pi}{26}\bigg)\cdot \cos \bigg(\dfrac{7\pi}{26}\bigg)+\quad 2\cos\bigg(\dfrac{13\pi}{26}\bigg)\cdot \cos\bigg(\dfrac{3\pi}{26}\bigg)\\\\\\.\qquad \qquad =2\cos \bigg(\dfrac{\pi}{2}\bigg)\cdot \cos \bigg(\dfrac{7\pi}{26}\bigg)+\quad 2\cos\bigg(\dfrac{\pi}{2}\bigg)\cdot \cos\bigg(\dfrac{3\pi}{26}\bigg)\\\\\\\text{Factor:}\qquad =2\cos\bigg(\dfrac{\pi}{2}\bigg)\bigg[ \cos \bigg(\dfrac{7\pi}{26}\bigg)+ \cos \bigg(\dfrac{3\pi}{26}\bigg)\bigg][/tex]
[tex]\text{Unit Circle:}\quad 2(0)\bigg[ \cos \bigg(\dfrac{7\pi}{26}\bigg)+ \cos \bigg(\dfrac{3\pi}{26}\bigg)\bigg][/tex]
Product of Zero 0
LHS = RHS: 0 = 0 [tex]\checkmark[/tex]
Related Questions
Will Mark Brainliest 15 POINTS Please find the slope!
Answers
Answer:
0.3
Step-by-step explanation:
7. How does using a bar diagram help you in predicting the solution to ratio and rate problems?
8. How can you use a bar diagram to check the accuracy of the solution to a ratio or rate problem?
My sister need help asap
Answers
Answer:
7) ratio and rate are actually the same thing
they gives a fixed value when two quantities when plotted on a bar diagram helps in determining as well as predicting the solution of the problem.I'm not sure about 7
The length of a rectangle is 3 times its width. The perimeter of the rectangle is 56 inches. What are the dimensions of the rectangle?
Answers
Answer:
Width=7
Length=21
Step-by-step explanation:
Width=x
length=3x
x+x+3x+3x=56
8x=56
x=7
width = x = 7
length = 3x = 21
Answer:
Length = 21 and Width = 7
Step-by-step explanation:
Length (L)= 3x width (W)
L = 3W
Perimeter (P) = 56
Perimeter = 2L + 2W
56 = 2(3W) + 2W
56 = 6W + 2W
56 = 8W
W = 56/8
W = 7
L = 3W
L = 3(7)
L = 21
therefore Length = 21 and Width = 7
In the diagram, JOK and MON are straight lines. Angle NOP and Angle NOQ are complimentary angles. Calculate the value of x - y.
Answers
Answer:
x - y = 118
Step-by-step explanation:
Since ∠ NOP and ∠ NOQ are complimentary then ∠ POQ = 90°
Since JOK is a straight line then
∠ JOP + ∠ POQ + ∠ QOK = 180 , that is
76 + 90 + y = 180
166 + y = 180 ( subtract 166 from both sides )
y = 14
Since MON is a straight line then
∠ MOK + ∠ KOQ + ∠ QON = 180, that is
x + 14 + 34 = 180
x + 48 = 180 ( subtract 48 from both sides )
x = 132
Thus
x - y = 132 - 14 = 118
10-9/3 with an explanation
Answers
Answer:
Brainliest!
Step-by-step explanation:
you know -9/3 = -3
10-3 = 7
so the answer is 7
10+-3=7
A bank charges a 14% interest per annum on a loan. What is the interest rate if charged yearly?
Answers
Answer: Per annum means yearly so the interest rate will be 14% as well.
Step-by-step explanation:
The temperature at 9:00pm one evening was 40 Fahrenheit. Over the next 4 hours the temperature dropped at n average rate of 3 per hour. What was the temperature at 1:00am?
Answers
Answer:
28 degrees Fahrenheit
Step-by-step explanation:
If the temperature at 9:00pm one evening was 40 Fahrenheit. And for the next 3 hour it dropped 3 degrees per hour then it would be
40 - 4 times 3 =
40 - ( 4 times 3 ) =
40 - 12 = 28 degrees Fahrenheit
please help me on this
Answers
Answer:
x = 2Step-by-step explanation:
9•8 = 72
x² = 288÷72
x² = 4 ⇒ x = 2
A medical rescue helicopter is flying at an average speed of 172 miles per hour toward its base hospital. At 2:42 p.m., the
helicopter is 80 miles from the hospital. Use this information for Items 4-5.
Which equation can be used to determine m, the number of minutes it will take the helicopter to reach the
hospital?
Answers
Answer:
The equation that can be used to determine m, the number of minutes it will take the helicopter to reach the hospital is [tex]172 \times (\frac{m}{60} ) = 80[/tex].
Step-by-step explanation:
We are given that a medical rescue helicopter is flying at an average speed of 172 miles per hour toward its base hospital. At 2:42 p.m., the helicopter is 80 miles from the hospital.
As we know that the Distance-Speed-Time formula is given by;
[tex]\text{Distance} = \text{Speed}\times \text{Time}[/tex]
Here, Distance = 80 miles
Speed = 172 miles per hour
Time = m (the number of minutes)
Firstly, as we can see that the speed is in miles per hour but the time is in minutes, so we will convert the time in hours, i,e;
Time = [tex]\frac{\text{m}}{60} \text{ (in hours)}[/tex]
So, [tex]\text{Distance} = \text{Speed}\times \text{Time}[/tex]
[tex]80 = 172 \times (\frac{\text{m}}{60})[/tex]
[tex]\text{m} = \frac{80 \times 60}{172}[/tex]
m = 27.91 ≈ 28 minutes.
Hence, it will take 28 minutes for the helicopter to reach the hospital.
Calculate the slope.
Answers
Answer: 2/3
Step-by-step explanation:
Since the line is going through the origin it slope will use the formula y/x = k where k is the slope. So you can use any point on the number line to determine the slope.
use the point (3,2) using the formula y/x = k divide the y by x.
k = 2/3
Answer: 0.67
Step-by-step explanation:
Look at the points (3,2), (6,4), and (9,6)
1. Write an equation to represent the distance (d) that a person can run in t hours if she runs at a speed of 4 miles per hour. 2. Write an equation to represent the total cost (c) of buying candy bars (b) at a cost of $0.98 per bar. If a teacher wants to buy 20 chocolate bars for her students, how much will she pay? 3. Write an equation to represent the number of lawns (l) mowed in d days by a company that mows 18 lawns per day. How many lawns does the company mow in 5 days?
Answers
Answer:
1. The equation that represent the distance (d) that a person can run in t hours is: d = 4t
2. The equation is: c = $0.98(20)
3. The equation is: L = 18(5)
Step-by-step explanation:
1. The variable d represents the distance over time, and t represents the hour in the equation so if you want to find the distance over time, you would say distance per hour. The per means to multiply, so every distance is equal to 4 miles per hour..
2. If the teacher wants to find out how much she will have to pay for 20 chocolate bar, she has to substitute 20 into the equation to replace b, which means bar. So the equation would be: total cost (c) = $0.98 × chocolate bars (b). Once substituted, the equation will be c = $0.98(20).
3. The problem said "mows 18 lawns per day" and "mow in 5 days", that means that you substitute 5 into the equation to replace the d in days, since you are multiplying 5 × 18.. Your new equation will be: L = 18(5), Total Lawns = 18 (lawns) per 5 (days).
Lee can make 18 cookies with two cups of flour. How many cookies can he make with three cups of flour?
Answers
Answer:
he can make 27 cookies.
Step-by-step explanation:
9×2 is 18
9×3 is 27
Answer:
27 cookies
Step-by-step explanation:
First find how many cookies one cup of flour can make:
18/2
9 cookies per one cup of flour.
Now find how many cookies three cups of flour can make:
9 cookies = 1 cup of flour
? = 3 cups of flour
9 × 3 = 27
Therefore:
3 cups of flour can make 27 cookies.
How many terms are shown? 3x-2y+4-3z
A. 1
B. 2
C. 3
D. 4
Answers
if two points are givin, then exactly one line can be drawn through those two points. which geomerty trem does the statement represent
Answers
Answer:
the correct answer is
Step-by-step explanation:
hope this helps u!!
Enter the appropriate abbreviations.
Answers
Answer: gal / min
Step-by-step explanation:
change to a whole or mixed 17/5
Answers
Answer:
3 2/5
Step-by-step explanation:
17/5
How many times does 5 go into 15
5*3 =15 3 times
17-15 =2 so there is 2 left over. This goes over the denominator
3 2/5
Answer:
3 2/5Step-by-step explanation:
[tex]17/5 = 17 \div 5 = 3\:remainder\: 2\\\\= 3\frac{2}{5}[/tex]
[tex]M\times 2^3\times 3^7=6^7.[/tex]. Find M.
Answers
Step-by-step explanation:
steps by steps are in the picture I hope this helps you!
Define the terms factor and quantity. Then for the expression −3(4+x)(z−2−y), list all of the factors, and specify which are quantities.
Answers
Answer:
A factor are numbers or variables that can be being multiplied to each other to get another number. A factor is a quantity which is used to multiply or divide another quantity to indicate a measurement difference
A quantity is the total number or amount and it is the subject in a given mathematical operation
In the expression, -3×(4 + x)×(z - 2 - y), the factors are;
-3, (4 + x), and (z - 2 - y)
The quantities are the values that are subject to the mathematical operations including;
3, 4, x, z, 2, and y
Step-by-step explanation:
LET x=0 x-2y=4 what is the value of y?
Solve for the missing variable: LET y=0: x-2y=4 what is the value of x?
Answers
Answer:
When x = 0, then y = -2
When y = 0, then x = 4
Step-by-step explanation:
We are given with the following equation;
x - 2y = 4
Now, we have to find the respective values of x and y for each value of x = 0 and y = 0.
Firstly, putting the value of x = 0;
x - 2y = 4
0 - 2y = 4
-2y = 4
y = [tex]\frac{4}{-2}[/tex] = -2
This means that when x = 0, then y = -2.
Similarly, putting the value of y = 0;
x - 2y = 4
[tex]x-(2\times 0)=4[/tex]
x - 0 = 4
x = 4
This means that when y = 0, then x = 4.
Please help! Offering brainiest and 5 stars with thanks
Answers
Answer:
The answer is 21 people
Answer:
[tex]\huge\boxed{12 \ People}[/tex]
Step-by-step explanation:
According to the ranges in Histogram:
People who took 4-6 hours to finish = 12 people.
calculate the total surface area of a cylinder whose radius is 7cm and height is 21cm.
1212
1227
1232
1242
Answers
Answer:
C. 1232
Step-by-step explanation:
A=2πrh+2πr2=2·π·7·21+2·π·72=1232.
Answer:
The answer is 1232cm^2
Step-by-step explanation:
Formula for total surface area of a cylinder is=2[tex]\pi[/tex]r²+2[tex]\pi[/tex]rh
radius=7 cm
height=21 cm
∴TSA= 2 x 3.14 x 7² + 2 x 3.14 x 7 x 21
TSA= 2 x 3.14 x 49 + 2 x 3.14 x 7 x 21
TSA=1232cm².
You can also use 22/7 for pile/[tex]\pi[/tex] instead of 3.14.
It's your choice.
Thanks.
In right angled triangle (not drawn to scale) measurment (in cm) of two sides are indicated in figure Find value of x in case. (pic is attached on which figure is drawn)
Answers
Answer:
5.29 units
Step-by-step explanation:
By Pythagoras theorem:
[tex] {6}^{2} + {x}^{2} = {8}^{2} \\ 36 + {x}^{2} = 64 \\ {x}^{2} = 64 - 36 \\ {x}^{2} = 28 \\ x = \sqrt{28} \\ x = 5.29150262 \: units \\ x \approx 5.29 \: units[/tex]
What is f(0) given f(x) = 5(x + 2)2 - 10?
Answers
Work Shown:
The idea is to replace x with 0 and then use PEMDAS to simplify.
f(x) = 5(x+2)^2 - 10
f(0) = 5(0+2)^2 - 10
f(0) = 5(2)^2 - 10
f(0) = 5(4) - 10
f(0) = 20-10
f(0) = 10
Answer:
10Step-by-step explanation:
[tex]f(x) =5(x+2)^2 -10\\\\f(0) = 5(0+2)^2 -10\\\\= 5(2)^2-10\\\\5(4)-10\\\\20-10\\\\f(0) =10[/tex]
Divide. Write the quotient in lowest terms 2 1/2 divided by 2 2/3
Answers
Answer:
15/16.
Step-by-step explanation:
2 1/2 = 5/2 and 2 2/3 = 8/3 so we have:
5/2 / 8/3 Invert the 8.3 and multiply:
= 5/2 * 3/8
= 15/16.
Answer:
The answer is
[tex] \frac{15}{16} [/tex]Step-by-step explanation:
[tex]2 \frac{1}{2} \div 2 \frac{2}{3} [/tex]To solve the expression convert the mixed number to an improper fraction
That's
[tex]2 \frac{1}{2} = \frac{5}{2} [/tex][tex]2 \frac{2}{3} = \frac{8}{3} [/tex]So we now have
[tex] \frac{5}{2} \div \frac{8}{3} [/tex]To solve this change the division sign to multiplication sign and reverse the second fraction
That's
[tex] \frac{5}{2} \times \frac{3}{8} [/tex]Multiply
We have the final answer as
[tex] \frac{15}{16} [/tex]Hope this helps you
Hi, I'm very fonfused on what to do here.
Answers
Answer:
C) 212.53
Step-by-step explanation:
3x60=180 (3 minutes is 180 seconds)
180+32.53=212.53 seconds
simplify : -2(3v -6)
with steps too please
Answers
Answer:
-6v - 12
v = -2
Step-by-step explanation:
Simplify:
Apply the rules of the distributed property by multiplying -2 and 3v and -2 and -6: -6v - 12Solve:
Now that we have our simplified form, we can find what v is. First divide each side by -6 to cancel out the -6 next to v. It should now look like this: v = -2What is f(-4) for the function f?
f(x) = 2x + 3
Answers
Answer:
[tex]\Huge \boxed{{f(-4)=-5}}[/tex]
Step-by-step explanation:
The function f(x) is given.
f(x) = 2x + 3
f(-4)
The input for the function f(x) is -4.
x is the input value.
x = -4
Replace x with -4.
f(-4) = 2(-4) + 3
Solve for the brackets.
f(-4) = -8 + 3
Evaluate.
f(-4) = -5
Answer: f(-4) = -5
Step-by-step explanation: Here we're given the function
f(x) = 2x + 3 and we're asked to find f(-4).
In other words, if we put a x into our function, we get a 2x + 3 out.
So what happens when we put a -4 into the function?
Well if we put a -4 into the function, that's f(-4), we get a 2(-4) + 3 out.
Now all we have to do is simplify on the right side.
2(-4) is -8 so we have -8 + 3 which is -5.
So f(-4) is -5.
Order the angle from smallest to larges
Answers
Answer:
BCA
Step-by-step explanation:
Explanation:
The smallest angle is always opposite the smallest side of a triangle. The largest angle is always opposite the largest side.
Side AC is the shortest, so angle B is the smallest.
Side BC is the longest, so angle A is the largest
Angle C must be between angles B and A.
1) A rectangular carpet has a perimeter of 288 inches. The length of the carpet is 96 inches more than the
width. What are the dimensions of the carpet?
Answers
Answer:
The width is 24 inches and the length is 120 inches.
Step-by-step explanation:
Let x represent the width of the carpet
The length can be represented by x + 96
Create an equation:
x + x + x + 96 + x + 96 = 288
Add like terms and solve for x:
4x + 192 = 288
4x = 96
x = 24
So, the width is 24 inches. Plug this into x + 96 to find the length:
x + 96
24 + 96
= 120
So, the width is 24 inches and the length is 120 inches.
20 points!!! pls help
Answers
Answer:
C
Step-by-step explanation: c and d are not aligned unlike the rest of them.