cos(4x + pi/5) - sin 2x = 0

Answers

Answer 1

cos(4x + π/5) - sin(2x) = 0

Since cos(x + π/2) = -sin(x), we can write

cos(4x + π/5) = cos(4x + π/2 - 3π/10) = -sin(4x - 3π/10)

Then we can absorb the negative signs into either sin expression, using the fact that sin(-x) = -sin(x):

-sin(4x - 3π/10) - sin(2x) = 0

sin(3π/10 - 4x) + sin(-2x) = 0

Recall that

• sin(a + b) = sin(a) cos(b) + cos(a) sin(b)

• sin(a - b) = sin(a) cos(b) - cos(a) sin(b)

==>   • 2 sin(a) cos(b) = sin(a + b) + sin(a - b)

We can further condense the left side in our equation if there exists a solution to

{ 3π/10 - 4x = a + b

{ -2x = a - b

We have

(a + b) + (a - b) = (3π/10 - 4x) + (-2x)

==>   2a = 3π/10 - 6x

==>   a = 3π/20 - 3x

(a + b) - (a - b) = (3π/10 - 4x) - (-2x)

==>   2b = 3π/10 - 2x

==>   b = 3π/20 - x

So in our equation, we have

sin(3π/10 - 4x) + sin(-2x) = 0

2 sin(3π/20 - 3x) cos(3π/20 - x) = 0

sin(3π/20 - 3x) cos(3π/20 - x) = 0

Solve for x :

sin(3π/20 - 3x) = 0   or   cos(3π/20 - x) = 0

[3π/20 - 3x = arcsin(0) + nπ   or   3π/20 - 3x = π - arcsin(0) + nπ]

  or   [3π/20 - x = arccos(0) + nπ   or   3π/20 - x = -arccos(0) + nπ]

[3π/20 - 3x = nπ   or   3π/20 - 3x = π + nπ]

  or   [3π/20 - x = π/2 + nπ   or   3π/20 - x = -π/2 + nπ]

[3x = 3π/20 - nπ   or   3x = -17π/20 - nπ]

  or   [x = -7π/20 - nπ   or   x = 13π/20 - nπ]

[x = π/20 - nπ/3   or   x = -17π/60 - nπ/3]

  or   [x = -7π/20 - nπ   or   x = 13π/20 - nπ]

(where n is any integer)


Related Questions

algebra hcf
10xyz and 15y²z²​

Answers

Answer:

5yz

Step-by-step explanation:

1st expression=10xyz

=5*2*x*y*z

2nd expression=15(y)2 (z)2

=5*3*y*y*z*z

therefore H.C.F=5yz

underlines are taking common.

HELP HURRY I WILL GIVE BRAINLIEST
Is 1.304 rational or irrational?

Answers

Answer:

Rational numbers are those numbers that are integers and can be expressed in the form of x/y where both numerator and denominator are integers whereas irrational numbers are those numbers which cannot be expressed in a fraction. ... The denominator of a rational number is a natural number(a non-zero number).

Answer:

Rational

Step-by-step explanation:

A rational number can be expressed in the form

[tex]\frac{a}{b}[/tex] ← where a and b are integers

Given

1.304

= 1 + [tex]\frac{304}{1000}[/tex]

= [tex]\frac{1304}{1000}[/tex] ← as a rational number

In Ellens Math class, there are 2 boys for every 3 girls. if there are 21 girls in the class, how many boys are in the classroom.

Answers

Answer:

14 boys

Step-by-step explanation:

Given,

There are 3 girls for every 2 boys

So,

For every 1 girl

[tex] = \frac{2}{3} \: boys [/tex]

Therefore,

For every 21 girls,

[tex] = \frac{2}{3} \times 21 \: boys[/tex]

= 14 boys (Ans)

Determine which ordered pair is a solution to the following equation x+y=8

Answers

Answer:

(8,0)

and infinite number of ordered pairs make the equation

true 4,4 ... 5,3 ... 9,-1 ....

the solution can be said to be the loation where the graph crosses the x axis that point is (8,0)

Step-by-step explanation:

2. Shelby and her two friends have 2 pies left after the bake sale after
school. They divide the pies evenly among themselves. How much pie did each
student receive?

Answers

Answer:

.67

Step-by-step explanation:

There are three friends and two pies. You are splitting the pies not the people so you divide 2 by 3 to get 0.66666667. Meaning each girl got .67 or around 6/10 of a pie.

In a sample of 600 college students, 87.2% said they graduated from high school. How many of the students graduated from high school?

Answers

Answer:

523.2 students

Step-by-step explanation:

87.2%×600=523.2 students

Answer:

523.2

Step-by-step explanation:

SEE THE IMAGE FOR SOLUTION

HOPE IT HELPS

HAVE A GREAT DAY

janessa is playing a board game with two friends. using a single die, one friend rolled a four, and the other friend rolled a three. janessa needs to roll a number higher than both friends in order to win the game, and she wants to calculate her probability of winning. Is the probability of Janessa winning an independent event or dependent event

Answers

Answer:

It is a dependent event, because it depends of the number she'll get rolling the die

PLEASE HELP
Seven more than the quotient of a number and 5 is equal to 4.
Use the variable b for the unknown number.

Answers

Answer:

7 + b/5 = 4

OR

b/5 + 7 = 4

Step-by-step explanation:

also, b = -15

In which of the following pairs of numbers is -6 larger than the first number, but smaller than the second number?

Answers

Answer:

-7, -6, -5

Step-by-step explanation:

-7 < -6

-5 > -6

-7 < -6 < -5

4.
For which discriminant is the graph possible?

A. b2 – 4ac = 0
B. b2 – 4ac = 6
C. b2 – 4ac = –2

Answers

Answer:

A. b2 – 4ac = 0

Step-by-step explanation:

Hey user☺☺

Option a is correct

Because the graph has only one solution.

As the graph touches the x-axis at one point that means that it will have only one solution for x. But we know that a quadratic equation has two solutions. So the graph will have two equal solution and therefore the discriminant will be 0.

Hope this will help☺☺

Exercise 1

4x...X4 =

7 times

Answers

It’s 4 power 7 understand though the demonstration down :)
7
4
25x7 67/7 was a pink rabbit random answer

What is the sum of all positive intergers from √8 to √42

Answers

√8 < √9 = 3

and

√42 > √36 = 6

which means the positive integers between √8 and √42 are 3, 4, 5, and 6, and their sum is 18.

What is the prime factorization of 81?
Enter your answer as a product of prime numbers, like 2 x 3, or as a single prime number, like 17.

Answers

Answer:

[tex]3^{4}[/tex]

Step-by-step explanation:

                 81

               27    3

            9  3    

        3  3

3*3*3*3 = [tex]3^{4}[/tex]

solve the following equations 6÷x=18​

Answers

[tex]\boxed{\underline{\bf \: ANS WER}}[/tex]

[tex] \sf \frac{6}{x} = 18 \\ [/tex]

Variable x cannot be equal to 0 as division by zero is not defined. Multiply both sides of the equation by x.

[tex] \sf \: 6=18x [/tex]

Swap sides so that all variable terms are on the left-hand side.

[tex] \sf \: 18x=6 [/tex]

Divide both sides by 18.

[tex] \sf \: x=\frac{6}{18} \\ [/tex]

Reduce the fraction [tex] \sf\frac{6}{18}[/tex] to its lowest terms by extracting and cancelling out 6.

[tex] \sf \: x=\frac{1}{3} \\ [/tex]

[tex] \sf \: x=\frac{1}{3}\approx \boxed{\underline{0.33... }}\\ [/tex]

______

Hope it helps.

ᏒᎯᎨᏁᏰᎾᏯᏕᎯᏝᎿ2222

The first three terms of a sequence are given. Round to the nearest thousandth (if
necessary).
6,2,2/3….
Find the 8th term.

Answers

Answer:

Just divide 2/3 by 3 (or multiply by 1/3), 6 times to get the answer.

Write two equivalent expressions that represent the situation. What is the difference in their elevations?
An airplane flies at an altitude of 26,000 feet. A submarine dives to a depth of 700 feet below sea level.

Answers

The answer is 25000 hope this help you out!

Evaluate the function: f(n)=3n-1 ; f(-1)= ?

Answers

Answer:

A certain brand of laundry detergent is manufactured for $5.80 and then marked up 35% by the local store before selling. The store offers a 15% discount with the purchase of three or more bottles of the detergent. Showing all work, determine the total cost, before tax, of four bottles of detergent. (10 points)

Step-by-step explanation:

A certain brand of laundry detergent is manufactured for $5.80 and then marked up 35% by the local store before selling. The store offers a 15% discount with the purchase of three or more bottles of the detergent. Showing all work, determine the total cost, before tax, of four bottles of detergent. (10 points)

Help with geometry please​

Answers

3x-10+42+58=180 because angles in a triangle add up to 180
X=30
Z is equal to 3x-10
So z=80
80+42= 122
180-122= 58 (angle C)
Y = 122 because angles on a straight line add up to 180

pq + 4; use p=4, and q = 4

Answers

Answer:

20

Step-by-step explanation:

pq + 4

Given:

p = 4

q = 4

We plug the numbers in:

pq + 4

4(4) + 4

16 + 4

20

The answer you are looking for is 20.

Since p=4 and q=4,

Therefore,

pq+4

Substitute each of the given values of the variables,

(4)(4)+4

16+4

20

What is the value of -2/3 x (-1/4)x(-24/4)

Answers

Answer:

-1

Step-by-step explanation:

Which equation represents a line which is parallel to the y-axis?
x = 6
O y = -1
Submit Answer
O x = 4y
Oy= 2 +1
PLS HELP ASAP

Answers

Answer:

x=6

Step-by-step explanation:

when there is no 'y' in equation, the line is always

parallel to y-axis

9. Tobias ran 3 miles. How many millimeters did he run? (1 mile = 1,610 meters)

Answers

Welcome to Brainly! I'm happy to help!

We see that there are 1,610 meters in a mile. However, we are looking for millimeters, not meters. But, knowing the meters will help us out.

A millimeter is a very small measurement. There are 1,000 millimeters in 1 meter. A meter is much larger. So, if we want to convert 1,610 meters to millimeters, there are going to be way more millimeters because they are so minute.

This means that we will have to multiply. We know that there are 1,000 millimeters in 1 meter, so if we multiply our meters by 1,000 (which is basically just adding 3 zeros), we will get the number of millimeters in one mile!

1,610×1,000=1,610,000 (one million six hundred and ten thousand!)

Don't forget that we are looking for 3 miles though, so we can take the number of millimeters in one mile and multiply by three.

1,610,000×3=4,830,000 (four million eight hundred and thirty thousand!)

So, Tobias ran 4,830,000 millimeters!

Have a wonderful day and keep on learning! :D

f(x) = (x + 1)(x - 5). What is the vertex?
(1,5)
(5.1)
(2.-9)
(-9,2)​

Answers

Answer:

(2, -9)

Step-by-step explanation:

f(x) = (x + 1)(x - 5)

[tex] =f(x) = {x}^{2} - 5x + x - 5[/tex]

[tex] = f(x) = {x}^{2} - 4x - 5[/tex]

[tex] = f(x) = {1x}^{2} - 4x - 5[/tex]

[tex] = f(x) = {1x}^{2} + ( - 4x) - 5[/tex]

= a = 1, b = -4

[tex] = x = \frac{ - 4}{2 \times 1} [/tex]

[tex] = x = - \frac{ - 4}{2} [/tex]

[tex] = x - ( - 2)[/tex]

[tex] = x = 2[/tex]

= f(x) = (x + 1) x (x - 5); x = 2

= f(2) = -9

= (2, -9)


Evaluate 9ab, for a = 5 and b =
- 7

Answers

Answer:

-315

Step-by-step explanation:

Plug in 5 as a and -7 as b into the term:

9ab

9(5)(-7)

Multiply:

= -315

So, the answer is -315.

[tex]\huge\boxed{\textsf{Hey there!}}\\\\\\\huge\boxed{\mathsf{9ab}}\\\huge\boxed{\mathsf{= 9(5)(-7)}}\\\huge\boxed{\mathsf{= 45(-7)}}\\\huge\boxed{\mathsf{= -315}}\\\huge\boxed{\frak{Answer: -315}}\huge\checkmark\\\\\huge\boxed{\textsf{Good luck on your assignment \& enjoy your day!}}\\\\\huge\boxed{\frak{Amphitrite1040:)}}[/tex]

f(x) = x − 7 and g(x) = x2 find f(g(−1))

Answers

Answer:

g (-1) = (-1)² = 1

f(g(-1)) = f(1)

f(1) = 1 - 7 = -6

put in order , smallest to largest 0.13 ,0.7 , 0.6

Answers

Answer:

0.13, 0.6, 0.7

Step-by-step explanation:

Basically when comparing a decimal from least to greatest look at the tenths place. Whoever's is the smallest, is the smallest decimal. Then you look at the second smallest etc. If two tenths are the same then you would compare the hundredths place so on.

The cost of a jacket increased from $50.00 to $59.00. What is the percentage increase of the cost of the jacket?

Answers

Answer- it increased 18%

Answer:

18%

Step-by-step explanation:

I know this because i am a smoot person  l o l. Hope this helps!

I need help on an assignment.

Answers

Answer:

i believe that answer would be D

Step-by-step explanation:

what are congruent triangles?​

Answers

Triangles that have all sides and angles the same length or degree.

Please give brainliest

Answer:

triangles that have the same size and shape.

helppppppppppppppppppppppppppppppppppp pleaseeeeeeeeeeeeeeeeee

Answers

Answer:

answer is D

Step-by-step explanation:

i promise good luck

Answer:

d

Step-by-step explanation:

change the fractions into improper fractions

then multiply nominators by nominators

then same for denominators

then simplify

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