1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Alexxandr [17]
2 years ago
15

Giải phương trình : 8cos 4 x – 4cos2x + sin4x – 4 = 0

Mathematics
1 answer:
alex41 [277]2 years ago
5 0

Answer:

Step-by-step explanation:

8(1+cos2x/2)^{2} -4c0s2x+sin4x-4=0\\2(1+2cos2x+cos^{2}2x )-4cos2x+sin4x-4=0\\2cos^{2} 2x+sin4x-2=0\\1+cos4x+sin4x-2=0\\cos4x+sin4x=1\\sin(4x+\pi /4)=sin\frac{\pi }{4} \\\left \{ {{4x+\frac{\pi }{4} =\frac{\pi }{4}+k2\pi  } \atop {4x+\frac{\pi }{4} =\frac{3\pi }{4} +k2\pi \\

You might be interested in
How do you solve algebraically 8x^2=18
vodka [1.7K]
That would be
x =  + \frac{ \sqrt[]{3} }{ \sqrt[]{2} }
BTW the plus sign is supposed to have this sign underneath it _
Good luck.
5 0
3 years ago
I keep putting in the formula but I keep getting the answer wrong​
Advocard [28]

Answer:

314 in²  (nearest whole number)

Step-by-step explanation:

<u>Radius of a regular polygon</u>: The distance from the <u>center</u> of the polygon to any vertex.  The radius of a hexagon is equal to the length of one side.

Therefore, from inspection of the given diagram:

  • radius = 11 in  ⇒  side length = 11 in

To find the area of a regular polygon, we first need to calculate the apothem.   The <u>apothem</u> is the line drawn from the center of the polygon to the midpoint of one of its sides.

\textsf{Length of apothem (a)}=\dfrac{s}{2 \tan\left(\frac{180^{\circ}}{n}\right)}

where:

  • s = length of one side
  • n = number of sides

Given:

  • s = 11 in
  • n = 6

Substitute the given values into the formula and solve for a:

\implies \textsf{a}=\dfrac{11}{2 \tan\left(\frac{180^{\circ}}{6}\right)}=\dfrac{11\sqrt{3}}{2}

<u>Area of a Regular Polygon</u>

\textsf{A}=\dfrac{n\:s\:a}{2}

where:

  • n = number of sides
  • s = length of one side
  • a = apothem

Given:

  • n = 6
  • s = 11
  • \textsf{a}=\dfrac{11\sqrt{3}}{2}

Substitute the given values into the formula and solve for A:

\implies \sf A=\dfrac{6 \cdot 11 \cdot \dfrac{11\sqrt{3}}{2}}{2}

\implies \sf A=314.3672216...

\implies \sf A=314\:\:in^2\:\:(nearest\:whole\:number)

8 0
2 years ago
A club with 31 members is to select five officers (president, vice president, secretary, treasurer, and historian). In how many
Ksivusya [100]
If you take 31*5 that equals = 155 ways! <span />
5 0
3 years ago
The Suarez family paid $16.00 for 4 movie tickets. How much would they have paid for 16 tickets?
Sergio039 [100]
Well its $16
 for 4 tickets so u multiply everything by four and get $64 for 16 tickets
8 0
3 years ago
Read 2 more answers
What is the value of A when we rewrite<br> (5/2)^x +(5/2)^x+3 as A x (5/2)^x
elixir [45]

Answer:

Step-by-step explanation:

(\frac{5}{2})^{x}+(\frac{5}{2})^{(x+3)}=(\frac{5}{2})^{x}+(\frac{5}{2})^{x}*(\frac{5}{2})^{3}\\\\=(\frac{5}{2})^{x}*[1+(\frac{5}{2})^{3}]

Therefore,

A=1+(\frac{5}{2})^{3}

3 0
3 years ago
Other questions:
  • How am I suppose to answer this question
    9·1 answer
  • Help me get the area of triangles and parallelograms
    10·1 answer
  • Mrs.Feinstein recorded the weight, in pounds, recorded of each of her 8 great-grandchildren. Her data are shown.
    11·1 answer
  • of the total 1,034,884 people infected in the us if 641,628 caucasians are infected write the percent it represents in the unite
    10·1 answer
  • PLEASE HELP!
    8·1 answer
  • Writing expressions - <br> the sum of 4 twelves and 7 sixteens
    8·2 answers
  • 24/7 as a fixed number
    12·2 answers
  • Will mark brainliest! Please help I have no idea!
    13·2 answers
  • What is the answer to y=-2(-3/2)-9
    8·2 answers
  • Locate root 9.8 on number line
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!