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
Bingel [31]
3 years ago
12

How to express cos 3x in terms of cosx

Mathematics
1 answer:
Elena-2011 [213]3 years ago
5 0
\cos3x=\cos(x+2x)=\cos x\cos2x-\sin x\sin2x
=\cos x(\cos^2x-\sin^2x)-2\sin^2x\cos x
=\cos^3x-\cos x\sin^2x-2\sin^2x\cos x
=\cos^3x-3\cos x\sin^2x
=\cos^3x-3\cos x(1-\cos^2x)
=\cos^3x+3\cos^3x-3\cos x
=4\cos^3x-3\cos x
You might be interested in
Billy charges $15 to mow a yard. He needs at least $200 for the new bicycle that he wants. Write and solve an inequality to find
Marta_Voda [28]
He has to mow 14 yard to get at least 200 but he will have 10 extra dollars.
3 0
3 years ago
Read 2 more answers
The water level in a lake was 22 inches below normal at the beginning of March. The water level decreased by 3 1/6 inches in Mar
Vinvika [58]
At the beginning it was 22 inches below normal (-22).
Then it decreased by 3 1/6 (-19/6).
Then increased by 1 6/7 (+13/7)

-22 - 19/6 + 13/7
-924/42 - 133/42 + 78/42
-1057/42 + 78/42
-979/42
-23 13/42

It was 23 13/42 inches below normal after April.
8 0
3 years ago
Ms Lewis is hiring a carpenter to repair her shed the cost of carpenter L is shown in the table
KiRa [710]

Based on the information given, it can be deduced that the initial cost will be $187 and the hourly rate is $72 per hour.

From the information given, the initial cost is $187. The cost for 2 hours is $259 and the cost for 3 hours is $331.

Therefore, the rate per hour will be:

= $259 - $187 = $72

The equation will then be:

= 187 + 72h

Lastly, the difference in the costs is $72.

Learn more about equations on:

brainly.com/question/13763238

4 0
2 years ago
Pls help will give brainlist if right
sergiy2304 [10]

Answer:

1) supplementary

2) ∠ABD = 180° - 123°

Step-by-step explanation:

3 0
3 years ago
A.12B Evaluate f(x)=-2x+13 for f(10)
Assoli18 [71]
-7 i believe :))))))
4 0
3 years ago
Other questions:
  • compare the decimal 6324. 50 as 6003 24.5 what comparison is correct 6, 3 24. 50 equals 6, 3 24.5 or 6003 24. 50 is greater than
    15·1 answer
  • Which quadrilaterals always have diagonals that are perpendicular?​
    9·2 answers
  • What is the greatest integer a, such that a^2 + 3b is less than (2b)^2, assuming that b is 5? Please answer and have a nice day!
    8·1 answer
  • Can I have help on 3?
    15·2 answers
  • Which number line shows the solution to the inequality 4x+ 5 > 9​
    15·1 answer
  • 7.865 rounded to the nearest whole number
    5·2 answers
  • Two banks are running promotions on savings accounts in anticipation of higher interest rates in the future.
    9·1 answer
  • The number of ice cubes in a drink and the temperature of the drink, what kind of association is that
    6·1 answer
  • How do you solve this?
    11·1 answer
  • What’s the length of AZ. If A is between Y and Z, Y A = 22, AZ = 16x, and Y Z = 166
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!