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
DerKrebs [107]
3 years ago
13

Please help me with this question!! I also need the steps

Mathematics
1 answer:
e-lub [12.9K]3 years ago
8 0

Hi there!

\large\boxed{x = \frac{\pi}{3} \text{ and } \pi}

We are given:

cos(7x)cos(4x) = -1 - sin(7x)sin(4x)

Begin by moving all terms with variables to one side:

cos(7x)cos(4x) + sin(7x)sin(4x) = -1

The corresponding trig identity is cos(A - B). Thus:

cos(7x - 4x) = cos(7x)cos(4x) + sin(7x)sin(4x) = -1

cos(3x) = -1

cos = -1 at  π, so:

3x = π

x = π/3

We can also find another solution. Let 3π = -1:

3x = 3π

x = π

Thus, solutions on [0, 2π) are π/3 and π.

You might be interested in
I need help desperitly
topjm [15]
Number one is 12. There is 12 cubes.
8 0
3 years ago
Math .. help! asap aleks is so hard
3241004551 [841]
Answer is squareroot of 21 or 4.58 in decimal
by pythagorean theorem



---
Mark me as brainliest if you find the solution helpful. thanks
---
3 0
3 years ago
7. Isosceles triangle ABC is shown below with legs that measure 8 inches and a vertex angle of 50D. (a) Determine the area of AB
Flura [38]

Answer:

<h2>The area of the triangle ABC is 32 square inches.</h2>

Step-by-step explanation:

We know that the given triangle is a right-isosceles triangle, which means its leg are equal.

The area of a triangle is defined as

A=\frac{1}{2}bh

Where b=8 and h=8. Replacing values, we have

A=\frac{1}{2} \times 8 \times 8 = 32 \ in^{2}

Therefore, the area of the triangle ABC is 32 square inches.

7 0
3 years ago
A street light is mounted at the top of a 15-ft-tall pole. A man 6 ft tall walks away from the pole with a speed of 5 ftys along
Sever21 [200]

25/3 ft/s is speed of the tip of his shadow moving when a man is 40 ft from the pole given that a street light is mounted at the top of a 15-ft-tall pole and the man is 6 ft tall who is walking away from the pole with a speed of 5 ft/s along a straight path. This can be obtained by considering this as a right angled triangle.

<h3>How fast is the tip of his shadow moving?</h3>

Let x be the length between man and the pole, y be the distance between the tip of the shadow and the pole.

Then y - x will be the length between the man and the tip of the shadow.

Since two triangles are similar, we can write

\frac{y-x}{y} =\frac{6}{15}

⇒15(y-x) = 6y

15 y - 15 x = 6y

9y = 15x

y = 15/9 x

y = 5/3 x

Differentiate both sides

dy/dt = 5/3 dx/dt

dy/dt is the speed of the tip of the shadow, dx/dt is the speed of the man.

Given that dx/dt = 5 ft/s

Thus dy/dt = (5/3)×5 ft/s

dy/dt = 25/3 ft/s

Hence 25/3 ft/s is speed of the tip of his shadow moving when a man is 40 ft from the pole given that a street light is mounted at the top of a 15-ft-tall pole and the man is 6 ft tall who is walking away from the pole with a speed of 5 ft/s along a straight path.

Learn more about similar triangles here:

brainly.com/question/8691470

#SPJ4

3 0
2 years ago
Which ordered pair is the solution to the system of equations?
r-ruslan [8.4K]

Step-by-step explanation:

y = 2x - 15

4x + 3y = -5

4x + 3(2x - 15) = -5

4x + 6x - 45 = -5

10x = 40

x = 40/10

x = 4

y = 2x - 15

y = 2(4) - 15

y = 8 - 15

y = -7

Solution = (4,-7)

Option → C

8 0
2 years ago
Other questions:
  • A cylindrical can of cat food has a diameter of 3.5 inches and a height of 1.25 inches A second brand of cat food is packaged in
    6·1 answer
  • Sin x = cos53° what is the value of x?
    6·1 answer
  • What sets do -51 belong too
    13·1 answer
  • If x+y= -10 and x-y= 2 what is the value of x?
    10·1 answer
  • Lloyd's Cereal company packages cereal in 1 pound boxes (16 ounces). A sample of 36 boxes is selected at random from the product
    7·2 answers
  • 5 people working for 6 hours per day they complete they task task in 16 days. How many days would it take 8 people if they worki
    6·2 answers
  • Calculate and express your answer in decimal form: 1/2 x 17 *
    13·1 answer
  • Hellllppppppp
    8·1 answer
  • The value of -7 + 24 ÷ (-3)(2) is _____.
    12·1 answer
  • Find the measure of the missing angle pls help!
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!