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
solniwko [45]
1 year ago
5

HELP ON THIS PROBLEM!! Solve the following 0deg< x< 360deg: cos x= cos 2x

Mathematics
1 answer:
blsea [12.9K]1 year ago
7 0

Answer:

x=0^\circ,120^\circ,240^\circ,360^\circ

Step-by-step explanation:

<u>Use identities to set the equation up as a quadratic</u>

\cos x=\cos 2x;\:0^\circ \leq x \leq 360^\circ\\\\\cos x=2\cos^2 x-1\\\\0=2\cos^2 x-\cos x-1

<u>Make the substitution u=cos(x) and solve the quadratic</u>

<u />0=2u^2-u-1\\\\0=(2u+1)(u-1)

\displaystyle 0=2u+1\\\\0=2\cos x+1\\\\-1=2\cos x\\\\-\frac{1}{2}=\cos x\\\\120^\circ,240^\circ=x

0=u-1\\\\0=\cos x-1\\\\1=\cos x\\\\0^\circ,360^\circ=x

Hence, x=0^\circ,120^\circ,240^\circ,360^\circ

You might be interested in
If f(1) = 1 and f(n + 1) = 5f(n) + 3 then find the value of f(4).
FrozenT [24]

Answer:

218

Step-by-step explanation:

Because we need f(n) to calculate f(n+1), we have to calculate our values one step at a time. Starting with f(1) = 1,

f(2) = 5(f(1)) + 3 = 5(1) + 3 = 5+3 = 8

f(3) = 5(8) + 3 = 40 + 3 = 43

f(4) = 5(43) + 3 = 215 + 3 = 218

4 0
2 years ago
If f(x) = 2x² + 5, then what is the remainder when f (x) is divided by x – 10?
photoshop1234 [79]

Answer:

Step-by-step explanation:

x - 10 = 0

x = 10

f(10) = 2*10² + 5 = 2*100 + 5 = 200 + 5

      = 205

Remainder = 205

3 0
3 years ago
Find the equation of the circle of the triangle, whose vertices are A(2,3) , B(5,4) and C(3,7)
Rufina [12.5K]

Answer:

Sasuke     A 2-3

Step-by-step explanation:

4 0
3 years ago
What is the measure of
Alona [7]
Yeh provide more info
7 0
3 years ago
The two triangles are similar. What is the value of x?
Ghella [55]

Answer:

x=5

Step-by-step explanation:

We can write ratios to help us solve

4x            12 +3

---------- = ------------

3x+1                 12

Using cross products

4x*12 = (3x+1) * (15)

48x = 45x +15

Subtract 45x from each side

3x =15

Divide by 3

3x/3 =15/3

x=5

5 0
2 years ago
Other questions:
  • Determine whether the point (2, 0) is a solution to the system of equations. Explain your reasoning in complete sentences
    6·2 answers
  • (6x^3 + 18x^2)– 3x^2 =
    7·1 answer
  • The number of students enrolled at a college is 12,000 and grows 4% each year. Complete parts (a) through (e).
    15·1 answer
  • 9 ft = __yd. WHO EVWR ASNWER GET BRAINLEST ANSWER
    15·1 answer
  • Prove your answer as to why 2 m, 2 m, and 4 m will or will not form a triangle.
    13·2 answers
  • The height of Mount Everest is 8,848 m and the height of Aconcagua is 6,962 m.
    14·2 answers
  • 3a. The average for the statistics exam was 75 and the standard deviation was 8.
    14·1 answer
  • Select two numbers that are more than 5 units away from 0.
    12·1 answer
  • What is the missing number in this pattern?<br> 0, 2, 6, ----, 30, 62
    11·2 answers
  • Giveing 15 points.Use the rectangle to find the measure of the following angles measure ane BAC=25
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!