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
11Alexandr11 [23.1K]
3 years ago
15

Solve 2cos^2x+5cosx+2=0

Mathematics
1 answer:
Nuetrik [128]3 years ago
6 0
2cos^2x+5cosx+2=0\\
x\in\\
\Delta=b^2-4ac\\
\Delta=9\\
\sqrt{\Delta}=3\\
cosx=1\\
or\\
cosx=-6\\
-6\notin\\

Then using trygonometric table or a graph we read that:
cosx=1\Leftrightarrow(x)=0

Period of cosinus function = 2π
So the last answer is x=0+2k\pi\\
You might be interested in
(4). Simplifying polynomials, help pls:) brainliest involved
Roman55 [17]

Answer:

Explanation:

To simplify a polynomial, we have to do two things: 1) combine like terms, and 2) rearrange the terms so that they're written in descending order of exponent.

First, we combine like terms, which requires us to identify the terms that can be added or subtracted from each other. Like terms always have the same variable (with the same exponent) attached to them. For example, you can add 1 "x-squared" to 2 "x-squareds" and get 3 "x-squareds", but 1 "x-squared" plus an "x" can't be combined because they're not like terms.

Let's identify some like terms below.

f(x)=−4x+3x2−7+9x−12x2−5x4

Here you can see that -4x and 9x are like terms. When we combine (add) -4x and 9x, we get 5x. So let's write 5x instead:

f(x)=5x+3x2−7−12x2−5x4

Let's do the same thing with the x-squared terms:

f(x)=5x+3x2−7−12x2−5x4

f(x)=5x−9x2−7−5x4

Now there are no like terms left. Our last step is to organize the terms so that x is written in descending power:

f(x)=−5x4−9x2+5x−7

Step-by-step explanation:

5 0
3 years ago
The temperature at a mountain base camp was −3 degrees Celsius on Monday. Tuesday morning, the temperature was 2 degrees Celsius
guapka [62]

Answer: -9 degrees Celsius

Step-by-step explanation: You subtract two degrees from -3 and get -5 (-3-2=-5). Then, you subtract 4 degrees from -5 and get the answer of -9 degrees Celsius.

6 0
3 years ago
Read 2 more answers
1/2x+5=10 whats the value of the variable
svlad2 [7]

Answer:

1/2x+5=10

subtracting 5 from both sides 1/2x+5-5=10-5

1/2x=5

divide both sides by 1/2

1/2x÷1/2=5÷1/2

x=5×2/1

x=10

7 0
3 years ago
Find the missing side of triangle
Anna11 [10]

Answer:

x = 50

Step-by-step explanation:

Using Pythagoras' identity in the right triangle.

The square on the hypotenuse is equal to the sum of the squares on the other two sides , then

x² = 48² + 14² = 2304 + 196 = 2500 ( take the square root of both sides )

x = \sqrt{2500} = 50

5 0
3 years ago
Read 2 more answers
Please helpppppppppppppppp
Mazyrski [523]
Answer: y = 3/2x + 4

Explanation:
When you count on the graph, you can see that you have to move three spaces up and 2 spaces to the right to get to the next point. So that means our slope of the equation is 3/2

When we look at the y axis, we can see that the line intercepts it at (0,4). That would make our y intercept 4

So the equation would be y = 3/2x + 4
8 0
3 years ago
Other questions:
  • If f(x)=2x+7 and g(x)=11x-4, find (f+g)x.
    5·1 answer
  • How do I simplify this
    7·1 answer
  • Some number is tripled and then cut in half.The result is increased by 5, and is equal to 20
    6·1 answer
  • PLEASE HELP ASAP WITH NUMBER 7!!
    14·1 answer
  • What value of x makes the equation true?<br> -1=1 – 4(-5+4x) – 4x
    13·1 answer
  • This was a accident lol
    7·1 answer
  • In a city school of 900 students, 38% of the students are on the honor roll
    10·1 answer
  • Which has the greatest value -10, -3, 6, 9
    10·1 answer
  • Where does x go in the fraction?<br>15/100 = ?/?<br>​
    7·2 answers
  • sammi is trying to wrap a gift for her brother. the gift fits into a cube-shaped box with a side length of 9 inches. how many sq
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!