which of the following are solutions to the equation 2cos2x-1=0

Which Of The Following Are Solutions To The Equation 2cos2x-1=0

Answers

Answer 1

Answer:

x = π/4 and 5π/4

Step-by-step explanation:

Given the expression;

2cos²x - 1 = 0

2cos²x = 0+1

2cos²x = 1

cos²x = 1/2

cos x = ±√1/2

cos x = ±0.7071

x = arccos(±0.7071)

x = ±45 degrees

Convert to radians

Sence 180° = π rad

45°  = x

x = 45π/180

x = π/4

If x = -45°

Since cos is negative in the 3rd quadrant

x = 180 + 45

x = 225°

x = 225π/180

x = 45π/36

x = 5π/4


Related Questions

Can someone help me with this math homework please!

Answers

Answer:

11.2

Step-by-step explanation:

[tex]p =\frac{160.16}{14.3}=\frac{160.16*10}{14.3*10}\\\\p = \frac{1601.6}{143}\\\\[/tex]

p = 11.2

Answer:

The person above me is correct I just did the work and I got the same answer as them :)

Step-by-step explanation:

what is the y-coordinate of the red point?

Answers

The y-coordinate of the red point is -3.

if$3=£2 and Rs. 325=$3, how many pound(£) will be equal to Rs. 39000​

Answers

Answer:

Rupees 39,000 are

378.63 Pound sterling

Darcy's harvests 8 3/4 acres of corn every 5/6 hours. How much corn can she collect in a hour. ? =Amount of acres of corn done in a hour.

Answers

Answer:

Step-by-step explanation:

Acres of corn harvested : time taken = 8 3/4 : 5/6

How much corn can she collect in a hour. ?

Let

x = Acres of corn harvested

Acres of corn harvested : time taken = x : 1

8 3/4 : 5/6 = x : 1

35/4 : 5/6 = x : 1

35/4 ÷ 5/6 = x/1

35/4 × 6/5 = x/1

35*6/4*5 = x/1

210/20 = x/1

210 * 1 = 20 * x

210 = 20x

x = 210/20

= 10 1/2 acres

x = Acres of corn harvested = 10 1/2 acres

For every 19 litres of petrol a car can run for 50 km . How much petrol do you need ( to 1 DP ) to ensure the car has enough petrol of a trip that is 130 km

Answers

Answer:

49.4 liters

Step-by-step explanation:

we have the basic ratio between liters of petrol (gasoline) and distance driven :

19/50

now, the same ratio has to apply, when we talk about 130 km instead of just 50.

so,

19/50 = x/130

x = 130×19/50 = 13×19/5 = 49.4 liters

if I may add, this is a very bad or at least very, very big car based on today's standards ...


In a college of 400 students, 45% are girls. Of the boys, 30% are football
players. How many boys are football players?

Answers

Of 400 students
No of girls = 0.45 x 400= 180
No of Boys = 400-180=220
Of the. No of boys 30% are football players =0.30 x 220 = 66

10 points!!!!!:)

Describe the graph of the function.

[tex]y = \sqrt{x + 3} [/tex]
a). the graph is a radical function y=sqrt(x) shifted 3 units right.
b). the graph is a radical function y=sqrt(x) 3 units left.
c). the graph is of exponential growth.
d). the graph is an absolute value function with vertex (-3,0).

pls help me:).

Answers

Answer:

b) y=sqrt(x) shifted 3 units left

Step-by-step explanation:

3rd line in the attached table:

f(x+3) = sqrt(x+3) horizontal translation left 3 units

What is an equation of the line that is parallel to y = 3x - 8 and passes
through the point (4,-5)?

Answers

Answer:

[tex]y=3x-17[/tex]

Step-by-step explanation:

Parallel equations always share a slope.

So since we know the slope and a point the equation needs to pass through we can plug in the values and replace -8 with [tex]b[/tex]

[tex]-5=3(4)+b[/tex]

simplify both sides

[tex]-5=12+b[/tex]

isolate the variable

[tex]-17=b[/tex]

plug [tex]b[/tex] back into the equation and you get

[tex]y=3x-17[/tex]

Answer:

y = 3 x + 11

 Explanation:

Parallel lines have the same slopes.

The slope of the new line will have the same slope as the given line:

y = 3 x − 4

⇒ m = 3

One point on the line is given,  

( − 2  5 ) .

This is  ( x 1  y 1 )

The formula for slope is  

m = ( change in y values/ change in x-values ) =  y 2  −  y 1/ x 2 − x 1

If you have the slope and one point , substitute them into a formula which is based on the formula for slope given above.

y  −  y 1 =  m  ( x  −  x 1 )  

y  −  5  =  3 ( x  −  ( − 2 ) )

y  −  5  =  3 ( x + 2 )

Simplify to get the required equation of the line.

y  =  3 x  +  6  +  5

y  =  3 x  +  11

Step-by-step explanation:

Find P(5) given P(x) = 4 - 1

Answers

Answer:6

Step-by-step explanation:

sorry if im wrong

Factor using the perfect squares method:

x^2 - 3x + 16

Answers

Answer:

what are the answer choice?

Step-by-step explanation:

Which ordered pair makes both inequalities true? y < 3x – 1 y > –x + 4 On a coordinate plane, 2 straight lines are shown. The first dashed line has a positive slope and goes through (0, negative 1) and (1, 2). Everything to the right of the line is shaded. The second solid line has a negative slope and goes through (0, 4) and (4, 0). Everything above the line is shaded.

Answers

Answer:

None of the options is true

Step-by-step explanation:

Given

[tex]y &lt; 3x - 1[/tex]

[tex]y &gt; -x + 4[/tex]

Required

Which makes the above inequality true

The missing options are:

[tex](4,0)\ (1,2)\ (0,4)\ (2,1)[/tex]

[tex](a)\ (x,y) = (4,0)[/tex]

Substitute values for x and y in the inequalities

[tex]y &lt; 3x - 1[/tex]

[tex]0<3*4 - 1[/tex]

[tex]0<12 - 1[/tex]

[tex]0<11[/tex] ---- This is true

[tex]y &gt; -x + 4[/tex]

[tex]0 > -4 + 4[/tex]

[tex]0 > 0[/tex] --- This is false

[tex](b)\ (x,y) = (1,2)[/tex]

Substitute values for x and y in the inequalities

[tex]y &lt; 3x - 1[/tex]

[tex]2<3 * 1 - 1[/tex]

[tex]2<3 - 1[/tex]

[tex]2<2[/tex] --- This is false (no need to check the second inequality)

[tex](c)\ (x,y) = (0,4)[/tex]

Substitute values for x and y in the inequalities

[tex]y &lt; 3x - 1[/tex]

[tex]4< 3*0-1[/tex]

[tex]4< 0-1[/tex]

[tex]4<-1[/tex] --- This is false (no need to check the second inequality)

[tex](d)\ (x,y) = (2,1)[/tex]

Substitute values for x and y in the inequalities

[tex]y &lt; 3x - 1[/tex]

[tex]1<3*2-1[/tex]

[tex]1<6-1[/tex]

[tex]1<5[/tex] --- This is true

[tex]y &gt; -x + 4[/tex]

[tex]1 > -2+4[/tex]

[tex]1 > 2[/tex] -- This is false

Hence, none of the options is true

find x
(4x - 3) – ( x + 5) = 3(10 - x)
please.....

Answers

Answer: 19/3

Step-by-step explanation:

[tex]4x+3-x-5=30-3x\\\\3x-8=30-3x\\\\6x-8=30\\\\6x=38\\\\x=\frac{19}{3}[/tex]

What is the vertex of
y= 3/4x^2+3x+2

Answers

Answer:

The vertex is located at (-2,-1)

Step-by-step explanation:

The person above me is correct

Which number line represents the solutions to -2x = -6?

Answers

Answer:

3

Step-by-step explanation:

-2x = -6

or, x = -6 / -2

or, x = 3

Evan, James, and Burt are fishing in a lake that has 200 fish. They are going to be fishing for three hours. What is the probability that they each will catch 3 fish?

Answers

Answer:

The probability that they each will catch 3 fish is 0.000063956

Step-by-step explanation:

The hyper geometric distribution is used to solve this as it has a population, a sample , number of successes  for both the population and sample.

Here

Population size= N =200

Sample size= n =9= (3*3)

Number of successes in population = k = 3 hours

Number of successes in sample = x= 3

Applying the hyper geometric distribution

P (x=3) = kCx *(N-k) C (n-x)/ N Cn

   = 3 C 3 * 197 C 6/ 200 C 9

    =0.000063956

The probability that they each will catch 3 fish is 0.000063956

Emily and Kylie are 140 miles apart, traveling towards each other. If Kylie travels 12 mph and Emily travels 8 mph how long until they meet?

Answers

Answer: 7 hr

Step-by-step explanation:

Given

Distance between Emily and Kylie is [tex]140\ \text{miles}[/tex]

Speed of Emily [tex]v_e=12\ mph[/tex]

Speed of Kylie [tex]v_k=8\ mph[/tex]

Distance traveled by Emily [tex]\Rightarrow d_e=12t[/tex]

Distance traveled by Kylie [tex]\Rightarrow d_k=8t[/tex]

[tex]\Rightarrow 12t+8t=140\\\Rightarrow 20t=140\\\Rightarrow t=7\ hr[/tex]

They will meet after 7 hour.

What number, divided by 3/7 , will result in a value of 2 1/3?

Answers

bro you still in school??

is AC greater than, less than, or equal to BC? explain your reasoning

Answers

Answer:

AC is greater than BC

Step-by-step explanation:

First, we know that the angle of a straight line is 180°, so angle B as a whole is equal to 180 degrees. Therefore, angle YBC + angle ABC = 180 degrees. As angle YBC is a right angle, signified by the small square on the angle, it is 90 degrees. Therefore,

90 degrees + angle ABC = 180 degrees

subtract 90 degrees from both sides to isolate angle ABC

angle ABC = 90 degrees

Therefore, as angle ABC is equal to 90 degrees, and a right angle is 90 degrees, triangle ABC has a right angle, making it a right triangle.

In a right triangle, using the Pythagorean Theorem, the square of the side opposite the right angle is equal to the sum of the squares of the other side. Since side AC is opposite the right angle, we can say that

AC² = AB² + BC²

As the length of a side has to be greater than 0, we can say that

AC² = AB² + BC²

AB² > 0

AC² > BC²

square root both sides

AC > BC

Therefore, AC is greater than BC

Write the equation for a parabola with a focus at (6,-4) and a directrix at y= -7

Answers

Given:

The focus of the parabola is at (6,-4).

Directrix at y=-7.

To find:

The equation of the parabola.

Solution:

The general equation of a parabola is:

[tex]y=\dfrac{1}{4p}(x-h)^2+k[/tex]                  ...(i)

Where, (h,k) is vertex, (h,k+p) is the focus and y=k-p is the directrix.

The focus of the parabola is at (6,-4).

[tex](h,k+p)=(6,-4)[/tex]

On comparing both sides, we get

[tex]h=6[/tex]

[tex]k+p=-4[/tex]                            ...(ii)

Directrix at y=-7. So,

[tex]k-p=-7[/tex]                            ...(iii)

Adding (ii) and (iii), we get

[tex]2k=-11[/tex]

[tex]k=\dfrac{-11}{2}[/tex]

[tex]k=-5.5[/tex]

Putting [tex]k=-5.5[/tex] in (ii), we get

[tex]-5.5+p=-4[/tex]

[tex]p=-4+5.5[/tex]

[tex]p=1.5[/tex]

Putting [tex]h=6, k=-5.5,p=1.5[/tex] in (i), we get

[tex]y=\dfrac{1}{4(1.5)}(x-6)^2+(-5.5)[/tex]

[tex]y=\dfrac{1}{6}(x-6)^2-5.5[/tex]

Therefore, the equation of the parabola is [tex]y=\dfrac{1}{6}(x-6)^2-5.5[/tex].

Can someone help me with this math homework please!

Answers

Answer:

First dropbox: 7h + 43 = 64

Second dropbox: $3

Step-by-step explanation:

Here's what we know about the question so far:

$43 is the initial fee

The rototiller worked for 7 hours

$64 is the total cost (including initial fee)

h = hourly fee

The answer should be 7h + 43 = 64 because:

- It includes the initial fee of $43

- It sets the equation equal to $64, which is the total cost

- The hourly fee is being multiplied with 7 hours, which is correct since the h variable is hourly (not sure how to explain this part ;w; )

For the 2nd drop box, we will use basic algebra to solve for h:

7h + 43 = 64

(subtract both sides by 43)

7h = 21

(divide both sides by 7)

h = 3

There's your 2 answers!

Hope it helps (●'◡'●)

Please help me! ❤️ I got stuck on this and really need some help

Answers

Answer:

0,-4

-2.65,2.62

2.65,2.62

Step-by-step explanation:

[tex]0^2 = 0\\-2.65^2 =7.0225\\ 2.65^2 =7.0225[/tex]

[tex]y = x^2 - 4[/tex]

-4, 3.0225

[tex]-4^2 = 16\\3.0225^2=9.1355[/tex]

a therate ticket cost £63 plus a booking fee of 3%
what is the total price of the ticket

Answers

Answer:

Total amount of ticket free = £64.89

Step-by-step explanation:

Given:

Cost of theater ticket = £63 plus

Booking fee of theater ticket = 3%

Find:

Total amount of ticket free

Comutation:

Total amount of ticket free = Cost of theater ticket + Booking fee of theater ticket

Total amount of ticket free = 63 + 3%

Total amount of ticket free = 63 + 1.89

Total amount of ticket free = 64.89

Total amount of ticket free = £64.89

52.3 X 16.0 please help me thank you so much !

Answers

Answer:

836.8

Step-by-step explanation:

PLEASE HELP!! You are playing a game in which you must flip a coin and then roll a die. What is the probability of flipping a tails and then rolling a five?

Answers

The chances of that are 1/12 which is 0.083%
Answer:  1/12

===========================================================

Explanation:

1/2 is the probability of flipping tails because we have one side labeled tails out of 2 sides total.

1/6 is the probability of rolling a 5, because there's one side we want out of 6 total.

The two events (flipping the coin and rolling the die) are independent, allowing us to multiply those previously mentioned fractions:

(1/2)*(1/6) = (1*1)/(2*6) = 1/12

Evaluate the function. f(x)=3x^2 −4x Find f(−1)

Answers

Answer:

7

Step-by-step explanation:

evaluate the function means substitute x=-1 and calculate

f(x) = 3x²-4x

f(-1) =f(x=-1) = 3(-1)²-4(-1) =3+4 =7, because (-1)²=1 and -4(-1) =4

To maintain a balanced diet, ensure that your food contains minimal amounts of certain ingredients. Which ingredient is missing in the sentence below?
One’s diet should include small amounts of fat, , and sugar.

Answers

Step-by-step explanation:

i think minerals and vitamins since they are micro nutrients

I have a lot of algebra problems. Someone help me even with this one please!

Answers

X -Y =44 will represent the number of glasses of ice tea .

Find the value of `x´ in the given parrallelogram.​

Answers

X=9

3x-12=x+6
2x-12=6
2x=18
X=9
The value of x is 9 cm in the given parrallelogram.

Step-by-step explanation:

=> (3x-12) =(x+6)

or,3x - x = 6 + 12

or,2x = 18

or,x = 18/2

: x=9#

Someone please help me ASAP! Worth 10 points

Answers

Answer:

(-1,-1)

Step-by-step explanation:

Step 1 identify coordinates of A

A is located at ( -3 , -3 )

Step 2 apply dilation by multiplying the x and y values of coordinate A by the scale factor

Given:

scale factor = 1/3

Coordinates of A: ( -3 , -3 )

* Multiply the x and y values by 1/3 *

( -3 * 1/3 , -3 * 1/3 ) -------> ( -1 , -1 )

The new coordinates would be (-1,-1)

multiply the coordinates of A by the scale factor given

3c(p-6)+4(p-6)= write the correct expression in factored form.

Answers

[tex]\tt\displaystyle\ 3c\underline{(p-6)}+4\underline{(p-6)}=(p-6)(3c+4)[/tex]

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