Prove that: (sin x - 2 sin³ x)/(2 cos³ x - cos x) = tan x​

Answers

Answer 1

[tex]\large\underline{\sf{Solution-}}[/tex]

We have to prove that:

[tex]\rm\longmapsto \dfrac{ \sin(x) - 2 \sin^{3} (x) }{2 \cos^{3} (x) - \cos(x) } = \tan(x) [/tex]

Taking LHS, we get:

[tex]\rm = \dfrac{ \sin(x) - 2 \sin^{3} (x) }{2 \cos^{3} (x) - \cos(x) }[/tex]

We can take sin(x) as common from numerator part. We get:

[tex]\rm = \dfrac{ \sin(x) \{1- 2 \sin^{2} (x) \}}{2 \cos^{3} (x) - \cos(x) }[/tex]

Similarly, we can take cos(x) as common from first two terms. We get:

[tex]\rm = \dfrac{ \sin(x) \{1- 2 \sin^{2} (x) \}}{ \cos(x) \{ 2 \cos^{2} (x) -1\}}[/tex]

[tex]\rm = \dfrac{ \sin(x) }{ \cos(x) } \cdot \dfrac{\{1- 2 \sin^{2} (x) \}}{\{ 2 \cos^{2} (x) -1\}}[/tex]

As we know that:

[tex]\rm\longmapsto \dfrac{ \sin(x) }{ \cos(x) } = \tan(x) [/tex]

We get:

[tex]\rm = \tan(x) \cdot \dfrac{\{1- 2 \sin^{2} (x) \}}{\{ 2 \cos^{2} (x) -1\}}[/tex]

Now, we will expand the terms in fraction:

[tex]\rm = \tan(x) \cdot \dfrac{\{1- \sin^{2} (x) - { \sin }^{2}(x) \}}{\{\cos^{2} (x) + \cos^{x}(x) -1\}}[/tex]

As we know that:

[tex]\rm \longmapsto \sin^{2}(x)+cos^{2}(x)=1[/tex]

[tex]\rm \longmapsto\cos^{2}(x)=1-sin^{2}(x)[/tex]

[tex]\rm \longmapsto\cos^{2}(x) - 1=-sin^{2}(x)[/tex]

Now substitute the values in the expression, we get:

[tex]\rm = \tan(x)\cdot \dfrac{ \cos^{2} (x)-{ \sin }^{2}(x)}{\cos^{2} (x) - \sin^{2} (x) }[/tex]

[tex]\rm = \tan(x)\cdot1[/tex]

[tex]\rm = \tan(x)[/tex]

Here, we notice that LHS = RHS

Proved.


Related Questions

Find the difference.

678-595.8

Answers

Answer:

82.2

Step-by-step explanation:

The difference is subtracting:

678 - 595.8 = 82.2

Answer:

82.2

Step-by-step explanation:

Check the image below.

gloria rode her bicycle 11.75 miles in the morning and 2.3 miles in the afternoon how many miles did gloria ride altogether.

Answers

Answer:

13.05

Step-by-step explanation:

1

11.75

+ 2.3

13.05

Answer:

14.05 miles

Step-by-step explanation:

To find the total amount of miles, we have to add 11.75 and 2.3, or 2.30. First, we add our hundredths:

0.05 + 0.00 = 0.05

Then, we add our tenths:

0.7 + 0.3 = 1

Then, we add our ones:

1 + 2 = 3

Finally, we add our tens:

10 + 0 = 10

Now, let's add all those numbers together. 10 + 3 + 1 + 0.05 = 14.05.

SHOW THE GRAPH AS WELL PLEASE
Plot the x- and y-intercepts to graph the equation. y=−12x−3

Answers

Answer:

(Hope this helps can I pls have brainlist (crown)☺️)

Step-by-step explanation:

To find the x-intercept, substitute in  0  for  y  and solve for  x To find the y-intercept, substitute in  0  for  x and solve for  y .

x-intercept(s):  ( − 6 , 0 )

y-intercept(s):  ( 0 , − 3 )

Use the slope-intercept form  y = m x + b to find the slope  m .

Slope: [tex]m = -\frac{1}{2}[/tex]

Graph in pic

(Credits: Symbolab)

Answer:

pls help

Step-by-step explanation:

hurry help!!!!! im doing a math portfolio and i dont remeber what is 15.33 rounded to the nearest whole is!!! please HELP ME ITS WORTH 30 POINTS OF MY GRADE!!

Answers

Answer:

15

Step-by-step explanation:

Cause 15.33 is closer to 15 than 16.

Answer:

15 is the answer I know I already told you but here it is again

Step-by-step explanation:

Maybe brainliest if I helped???

Its 15 because if the decimal after the whole number is less than 0.5 you go to the closest whole number down. Meaning whatever the whole number is attached to your decimal lower than 0.5 is your answer. If it's higher than 0.5 or IS 0.5 you round the nearest whole number, so one bigger than the number attached to your decimal. So if it was say:

15.67

The nearest whole would be 16

I hope I helped!

I have no idea how to draw the last one … any help plz

Answers

Answer:

The intersection of the x and y axis is one point one the line, another one is (1, 1). The range of y<x is below the line I just described.

Step-by-step explanation:

i need help with this question

Answers

Answer:

below

Step-by-step explanation:

I'm not absolutely know what are you asking for the answer, but this graph shows ...

The first 20 minutes he has a constant speed of 1.8/20=0.09 km/min progress to 1.8 km away from home, then has 10 minutes (from 20-30) stop at the spot.

Then he drive home with speed of 0.045 km/min (1.8/40=0.045) for 40 minutes to return to the start point.

fill in the blank (Geometry B)

Answers

Step-by-step explanation:

ratio

to

sind = d/e

sinf = f/e

Need help with this...pronto..please​

Answers

1) 130
2) 70
3) 21.5%
4) 77
5) 10

[tex]\sqrt{72x^{7} q^{8} }[/tex]

Answers

Attachment picture is the solution. Please mark me brain if you think it help. Thank you!


Suppose two trains leave a certain station, at the same time, traveling in opposite directions. One train travels 30 mph faster than the other. In 2.5 hours, the trains are 205 miles apart. Find the speed of each train


Answers

9514 1404 393

Answer:

  56 mph, 26 mph

Step-by-step explanation:

The trains are separating at the rate of (205 mi)/(2.5 h) = 82 mi/h. If we let s represent the speed of the slower train, then that sum of their speeds is ...

  s + (s+30) = 82

  2s = 52 . . . . . . . . . . subtract 30

  s = 26 . . . . . . . . . divide by 2

  s +30 = 56 . . . the speed of the other train

The speeds of the two trains are 56 mph and 26 mph.

NEEDS HELP PLEASE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answers

Answer:

3

Step-by-step explanation:

Kiran has 27 nickels and quarters in his pocket, worth a total of $2.75.
a. Write a system of equations to represent the relationships between the
number of nickels n, the number of dimes d, and the dollar amount in
this situation.

Answers

Answer:

[tex]\begin{cases}n+d = 27\\0.05n+0.10d = 2.75\\\end{cases}[/tex]

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

Explanation:

n = number of nickels

d = number of dimes

The n and d are placeholders for positive whole numbers.

Since we have 27 coins, we know that n+d = 27. The two subcounts must add to the grand total of 27. That explains how the first equation is set up.

The second equation is set up by looking at the dollar amount each group of coin brings in.

0.05n = amount of money in dollars the nickels bring in

0.10d =  amount of money in dollars the dimes bring in

0.05n+0.10d = total amount of money in dollars = 2.75

The single curly brace to the left of the equations tells the reader we're dealing with a system of equations. The equations are tied together.

there are 9 acorns in each pile. there are 8 piles. how many acorns are there in all? write an equation that can be used to solve this problem

Answers

Answer:

72 acorns.

Step-by-step explanation:

9 (acorns per pile)

             *

       8 (piles)

Answer:

9x8=72 making the answer 72 acorns in total.

6. Find the missing lengths of the sides.

Answers

Answer: D

30 60 90 trinagle rules

a=8

b=a sqaure root of 3 or 8square root of 3

c=2a or 2*8 or c=16

Step-by-step explanation:

Step-by-step explanation:

sin30°=8/c

1/2=8/c

8×2=c

16=c

tan30°=8/b

[tex] \frac{1}{ \sqrt{3} } = \frac{8}{b} \\ 8 \sqrt{3} = b[/tex]

option. d

Can someone please show me their working on these on how to work out?​

Answers

To rationalize essentially means to get rid of the radical.

The trick to all of these it to multiply the top and bottom by a radical that will turn the radical you have into the square root of a perfect square.

Part a: [tex]\dfrac{1}{2\sqrt{5}}[/tex]

One approach that will always work, but not be the smallest radical, is to just multiply by the radical that is already there.

In the case of [tex]\dfrac{1}{2\sqrt{5}}[/tex], you can multiply the top and bottom by [tex]\sqrt{5}[/tex], so you'll really do this:

     [tex]\dfrac{1}{2\sqrt{5}}\cdot\dfrac{\sqrt{5}}{\sqrt{5}} = \dfrac{1\cdot\sqrt{5}}{2\sqrt{5}\sqrt{5}}[/tex]

But in the bottom, [tex]\sqrt{5}\cdot\sqrt{5} = \sqrt{25}=5[/tex], so your work finishes out like this:

    [tex]\dfrac{1\cdot\sqrt{5}}{2\sqrt{5}\sqrt{5}} = \dfrac{\sqrt{5}}{2\sqrt{25}} = \dfrac{\sqrt{5}}{2\cdot5} = \dfrac{\sqrt{5}}{10}[/tex]

Part b: [tex]\dfrac{4}{5\sqrt{2}}[/tex]

In the case of [tex]\dfrac{4}{5\sqrt{2}}[/tex], you can multiply the top and bottom by [tex]\sqrt{2}[/tex], so you'll really do this:

     [tex]\dfrac{4}{5\sqrt{2}}\cdot\dfrac{\sqrt{2}}{\sqrt{2}}[/tex]

But in the bottom, [tex]\sqrt{2}\cdot\sqrt{2} = \sqrt{4}=2[/tex], so your work finishes out like this:

    [tex]\dfrac{4}{5\sqrt{2}}\cdot\dfrac{\sqrt{2}}{\sqrt{2}} = \dfrac{4\sqrt{2}}{5\sqrt{4}}=\dfrac{4\sqrt{2}}{5\cdot{2}}=\dfrac{4\sqrt{2}}{10}[/tex]

Sometimes the fraction can be reduced, so this should be reduced to [tex]\dfrac{2\sqrt{2}}{5}[/tex].

Looking at all the others, they'll follow this same approach and they will all reduce at the end.

Here's part c, for one more example.

Part c: [tex]\dfrac{3}{3\sqrt{2}}[/tex]

In the case of [tex]\dfrac{3}{3\sqrt{2}}[/tex], you can multiply the top and bottom by [tex]\sqrt{2}[/tex], but you should also reduce the initial fraction first.

     [tex]\dfrac{3}{3\sqrt{2}} = \dfrac{1}{1\cdot\sqrt{2}} = \dfrac{1}{\sqrt{2}}[/tex]

And now proceed with rationalizing:

    [tex]\dfrac{1}{\sqrt{2}} \cdot\dfrac{\sqrt{2}}{\sqrt{2}}[/tex]

But in the bottom, [tex]\sqrt{2}\cdot\sqrt{2} = \sqrt{4}=2[/tex], so your work finishes out like this:

    [tex]\dfrac{1}{\sqrt{2}}\cdot\dfrac{\sqrt{2}}{\sqrt{2}} = \dfrac{1\cdot\sqrt{2}}{\sqrt{4}}=\dfrac{\sqrt{2}}{{2}}[/tex]

And you're done.

Hopefully that helps you finish the rest of those.

To check your answers, here is the answer key for the rest:

part d:[tex]\dfrac{2\sqrt{6}}{5}[/tex]

part e:[tex]\dfrac{4\sqrt{2}}{3}[/tex]

part f:[tex]\dfrac{4\sqrt{5}}{7}[/tex]

part g:[tex]\dfrac{5\sqrt{10}}{3}[/tex]

part d:[tex]\dfrac{5\sqrt{2}}{3}[/tex]

Answer:

Step-by-step explanation:

(a) 1/(2 sqrt5) x (sqrt 5)/(sqrt5) = (sqrt 5)/10

(b) 4/(5bsqrt2) x (sqrt2)/(sqrt2) = (4sqrt2)/10 = (2sqrt2)/5

(c) 3/(3 sqrt2) x (sqrt2)/(sqrt2) =(sqrt2)/2

(d) 12 /(5 sqrt6) x (sqrt6)/(sqrt6) = (12sqrt6)/30 = (2sqrt6)5

(e) 8/(3 sqrt2) x (sqrt2)/(sqrt2) = (8 sqrt2)/6 = (4 sqrt2)/3

(f) 20/(7 sqrt5) x (sqrt5)/(sqrt5) = (20 sqrt5)/35 = (4 sqrt5)/7

(g) 50/(3 sqrt10) x (sqrt10)(sqrt10) = (50 sqrt10)/30 = (5sqrt10)/3

(h) 10/(3 sqrt2) x (sqrt2)/(sqrt2) = (10 sqrt2)6 = (5 sqrt2)/3

SHOW WORK. Algebra question. 100 POINTS. Easy

Answers

Answer:

D. -1 < x < 3

Step-by-step explanation:

The given function is negative between the x - intercepts  -1 and  3.Your choice is correct.

Answer:

D. -1 < x < 3

Step-by-step explanation:

The given function is negative between the x - intercepts  -1 and  3.

Your choice is correct.

find the value of 3x^3y-2xy^2 when x=3 and y=-2​

Answers

Answer:

sorry I don't remember bye I will try to remember

It’s -30
3^3^3^-2-2^3^-2^2 = -30

Convert the 144 km/h into meters per second

Answers

Answer:

144 Kilometers per Hour = 40 Meters per Second

Step-by-step explanation:

multiply the value in kilometers per hour by the conversion factor '0.27777777777778'.

So, 144 kilometers per hour = 144 × 0.27777777777778 = 40 meters per second.

please mark 4 brainliests.

Answer: 40 m/s

Step-by-step explanation: you can multiplied by 5/18 to convert km/h to m/s ,and you can multiplied by 18/5 to convert m/s to km/h.

help pls don't get it wrong I have an election tmr to see if I have good grades pls help​

Answers

SO, WHERE IS YOUR QUESTION?

BTW,,

[tex]join \: bunny \: squad[/tex]

[tex]just \: comment \: if \: you \: want[/tex]

#bunnysquad

#bunnysquadinbrainly

Answer:

pls mark my brainliest because you didn't wriitten coorect question

Step-by-step explanation:

If Kamina can do a job in 43 hours and Simon and Kamina working together can do the same job in 15 hours, find how
long it takes Simon to do the job alone.
hours
Answer:

Answers

Answer:

645/28 hours

Step-by-step explanation:

In 1 hour, Kamina does 1/43 of the job.

Simon takes x hour to do the job alone.

In 1 hour, Simon does 1/x of the job.

Together, they do the job is 15 hours, so in 1 hour, they do 1/15 of the job.

1/43 + 1/x = 1/15

15x/(645x) + 645/(645x) = 43x/(645x)

15x + 645 = 43x

28x = 645

x = 645/28

Hunter has a quarters and y dimes, having at least 18 coins worth at most
combined. A minimum of 4 of the coins are quarters and a minimum of 12
coins are dimes. Solve this system of inequalities graphically and determint
possible solution.

Answers

Answer:The number of nickles is 6  

The number of dims is 12 .

Step-by-step explanation:

Given as :

Sum of total number of dims and nickels coins = 18

The value of total combination = $1.50

Let The total number of dims = d

Let The total number of nickels = n

1 nickles = $0.05

1 dims = $0.1

According to question

Total number of dims and nickels coins = number of dims + number of nickels

Or, d + n = 18            .........1

And

$0.1 ×d + $0.05 ×n = $1.50

Or, 0.1 d + 0.05 n = 1.50            .........2

Now, Solving eq 1 an eq 2

0.1 × (d + n) - (0.1 d + 0.05 n) = 0.1 × 18 - 1.50

Or, (0.1 d - 0.1 d) + (0.1 n - 0.05 n) = 1.8 - 1.50

Or, 0 + 0.05 n = 0.3

Or, 0.05 n = 0.3

∴  n =

i.e n = 6

So, The number of nickles = n = 6

Put the value of n int eq 1

∵ d + n = 18

Or, d = 18 - n

Or, d = 18 - 6

i.e d = 12

So, The number of dims = d = 12

Hence, The number of nickles is 6 and the number of dims is 12 .

Step-by-step explanation:

A receptionist setting up tables for an event used 5 round tables and 2 rectangular tables.
Write a ratio that compares the number of round tables to the number of rectangular tables.
I

Answers

Answer:

5:2

or

5 to 2

or

5/2

Step-by-step explanation:

Write the recurring decimal 0.05 as a fraction in its simplest form

Answers

Answer:

1/20

Step-by-step explanation:

Step 1: Write the given number as the numerator and place 1 in the denominator right below the decimal point followed by the number of zeros required accordingly.

In this case, 0.05 has two numbers after the decimal, so, we place 100 in the denominator and remove the decimal point. This will make it 5/100

Step 2: Then, this fraction can be simplified. 5/100 = 1/20

Thus, 0.05 as a fraction is written as 1/20

Answer:

Step-by-step explanation:

let the fraction be a

a*100.....=0.05*100

100a......=05.00

99a....=0.05

100a= 5.00

99a=     0.05

   a=    4.95/99

Okay very important question.
When your doing pemdas , will you get a different answer then just calculating the problem on a calculator.

For example,

11x10-12 divided by 3

Calculated is 106

What’s the answer using pemdas?

Answers

Answer: It depends on how you put it in the calculator

Step-by-step explanation:

11x10=110

110-12=98

93/3 = 32.66

=
Find the slope of the graph of — 4x + 2y = 10 by
rewriting the equation in slope-intercept form.

Answers

Answer:

multiply by -1

Step-by-step explanation:

Slope intercept form : y = mx + b

-4x + 2y  =  10                  Solve the equation for y

+4x        = +4x    

    2y = 4x + 10

      y = 4x/2 + 10/2           Divide all terms by 2

    multiply by -1                   Simply

Jake has a wooden board that measures 8.25 feet long. He cuts the board into pieces that each measure 0.75 foot so he can make signs. If Jake earns $15.95 for each sign he sells, how much money can he earn from the signs he makes with this board?

Answers

Step-by-step explanation:

Answer:

Jake cuts the board into pieces that measure .75 feet each. Before cutting the board, it is 8.25 feet long. So, we must divide 8.25/.75 to find out how many pieces of board jake cut.

8.25/.75= 11 pieces

Since he makes $15.95 per sign, and there are 11 signs, we must multiply 15.95 by 11. This is equal to 175.45.

Therefore, jake can earn $175.45

Step-by-step explanation:

Can you give me brainliest?

0.35 x 9 = 3.15
Is this an overstatement understatement

Answers

[tex]over \: \: statement \: \\ \\ 0.35 \times 9 = 3.15 \\ \\ multiply \: 0.35 \times 9 \\ 3.15 = 3.15 \\ \\ so \: the \: answer \: is \: \: overstatemnt \\ \\ hope \: \: it \: \: helps[/tex]

y"+y'-6y = 12e^3t+12e^-2t

Answers

Answer

yc(T)=y"+y'-6y=0

Step-by-step explanation:

g(n) = 2n + 3
h(n)=n-1
Find (g•h)(n)

Answers

Answer:

Step-by-step explanation:

g(n) = 2n + 3

h(n) = n − 1

(g * h)(n) = g(h(n))

= g(n − 1)

= 2(n − 1) + 3

= 2n − 2 + 3

= 2n + 1


How much of the circle is shaded? Write your answer as a fraction in simplest form.

Answers

Answer:

5/28

Step-by-step explanation:

[tex] \frac{1}{4} + \frac{4}{7} = \frac{7 + 16}{28} = \frac{23}{28} \\ 1 - \frac{23}{28} = \frac{5}{28} [/tex]

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