If cosх A/2 =3/5, find the value of cos A​

Answers

Answer 1

Answer:

cosA = - [tex]\frac{7}{25}[/tex]

Step-by-step explanation:

Using the double angle identity

cos2A = 2cos²A - 1 , then

cosA = 2cos²([tex]\frac{A}{2}[/tex] ) - 1 , that is

cosA = 2 × ([tex]\frac{3}{5}[/tex] )² - 1

        = 2 × [tex]\frac{9}{25}[/tex] - 1

       = [tex]\frac{18}{25}[/tex] - [tex]\frac{25}{25}[/tex]

       = - [tex]\frac{7}{25}[/tex]


Related Questions

Yousuf had 117 marbles and Andrew had 23 marbles. Yousuf then gave some of his marbles to Andrew so that Yousuf ended with thrice as many marbles as Andrew. How many marbles did Yousuf give to Andrew?

Answers

Answer:

12

Step-by-step explanation:

117+23=140

140/4 = 35

35-23 = 12

Cho góc AOB = 100 độ vẽ OC là tia đối của tia OA , OM là phân giác của góc AOB . Tính góc COM?

Answers

Answer:

130 độ

Step-by-step explanation:

góc BOC= góc AOC-góc AOB

=180°-100°=80°

góc MOB = góc AOB/2=100°/2=50°( vì OM là tia phân giác của góc AOB)

góc COM= góc MOB + góc BOC

= 50° + 80°

= 130°

Six teachers and 12 students volunteer for a committee to discuss extra-curricular activities. How many committees of 5 people can be made if: a) there must be exactly 3 students on the committee b) there must be at least one teacher and at least one student on the committee (3 marks)

Answers

Answer:

a)[tex]X=3300[/tex]

b)[tex]Y=7770[/tex]

Step-by-step explanation:

From the question we are told that:

Number Teachers [tex]T=6[/tex]

Number Student [tex]S=12[/tex]

Number in committee [tex]n=5[/tex]

a) Generally the equation for exactly 3 students on the committee is mathematically given by

[tex]X=^{S}C_3*^{T}C_3[/tex]

[tex]X=^{12}C_3*^{6}C_3[/tex]

[tex]X=3300[/tex]

b) Generally the equation for at least one teacher and at least one student on the committee is mathematically given by

Total Ways-(no of ways of selection no teacher or student)

Where total Ways

[tex]T=^{(6+12)}C_5[/tex]

[tex]T=8568[/tex]

Therefore

[tex]Y=8568-^{6}C_0*^{12}C_5+^{12}C_0*^{6}C_5[/tex]

[tex]Y=8568-798[/tex]

[tex]Y=7770[/tex]

Find the area of a sector of a circle whose radius is 10 inches and whose
central angle is 52º.

Answers

Step-by-step explanation:

AS=∅πr²/360

where ∅=52°, R=10

AS=52°×π×(10)²/360

AS=14.4π

that is the answer

do you have another question to ask me

x + y = 10 . If y = 8, find the value of x

Answers

Answer:

2

Step-by-step explanation:

x + y = 10

y = 8

Substituting in equation,

x + 8 = 10

=>x = 10 - 8

=>x = 2

Find the value of x^3 + y^3 + z^3 – 3xyz if x^2 + y^2 + z^2 = 83 and x + y + z = 15​

Answers

Answer:

180

Step-by-step explanation:

Consider the equation x + y + z = 15

From algebraic identities, we know that (a + b + c)^2 = a^2 + b^2 + c^2 + 2(ab + bc + ca)

So,

(x + y + z)^2 = x^2 + y^2 + z^2 + 2(xy + yz + xz)

From the question, x^2 + y^2 + z^2 = 83 and x + y + z = 15

So,

152 = 83 + 2(xy + yz + xz)

=> 225 – 83 = 2(xy + yz + xz)

Or, xy + yz + xz = 142/2 = 71

Using algebraic identity a³ + b³ + c³ – 3abc = (a + b + c)(a² + b² + c² – ab – bc – ca),

x3 + y3 + z3 – 3xyz = (x + y + z)(x² + y² + z² – (xy + yz + xz))

Now,

x + y + z = 15, x² + y² + z² = 83 and xy + yz + xz = 71

So, x^3 + y^3 + z^3 – 3xyz = 15(83 – 71)

=> x^3 + y^3 + z^3 – 3xyz = 15 × 12

Or, x^3 + y^3 + z^3 – 3xyz = 180

Answered by GAUTHMATH

The circle below is centered at the origin and has a radius of 2. What is its equation?

Answers

I think is 1 radious

Can someone help with these two questions

Answers

Question 2

3rd part and 4th part are equivalent

Question 3

(i) 762,500

(ii) 7625

(iii) 0.007625

Answered by GauthMath please click thank you and comment thanks if you like it.

In the city of Chicago, the base fare for a taxi is $3.50, while each mile traveled costs $2. Select the graph that correctly displays the relationship between distance traveled and the taxi fare in Chicago.

Answers

Answer:

Option C Since the base fare is 3.5 approximately it would be option C

Answer:

B)

Step-by-step explanation:

The base fare, $3.50, is the y-intercept, and it is point (0. 3.5).

The rate per mile is the slope, and it is m = 2.

Only Graph B shows a y-intercept of 3.5 and a slope of 2.

Answer: B)

What is the quotient of the synthetic division problem below, written in polynomial form?

-1| 1 7 15 9 7​

Answers

Answer:

Step-by-step explanation:

If we have 5 terms to the right of the -1 outside the box thing, that means that our original polynomial is a 4th degree (the degree is one lower than the number of terms in order to allow for the constant which has no variable). Set up the synthetic division as shown in the problem. The rule is to bring down the first term, the 1 to the right of the box, multiply it by the number outside, -1, and put that product up under the next number in line inside the box. Like this:

-1 |   1    7     15     9     7

          -1                        

      1  

Now add straight down, multiply the sum by -1 and put that product up under the next term in line, the 15:

-1 |   1     7     15     9     7

            -1     -6              

      1     6  

Then add straight down again, multiply the sum by -1 and put that product up under the next term in line, the 9:

-1 |     1     7     15     9     7

              -1     -6    -9      

        1     6     9

Then do the same thing. Add straight down, multiply the sum by -1 and put the product up under the next term in line, the 7:

-1 |     1     7     15     9     7

              -1     -6    -9     0

        1     6      9     0     7

This is the final result. The last number, the 7 is the remainder, but the rest of it makes up what we call the depressed polynomial and is a polynomial that is one degree less than the degree we started with. So this depressed polynomial is a 3rd degree. The numbers are the coefficients on the x terms:

[tex]1x^3+6x^2+9x+0R7[/tex] or more simply stated:

[tex]x^3+6x^2+9xR7[/tex]

SOMEONE HELPPP MEEE OUTTT PLEASEEEE!!!

Answers

Answer:

3/5

Step-by-step explanation:

1. Establish the Equation: SinA = [tex]\frac{21}{35}[/tex]

2.  simplify [tex]\frac{3}{5}[/tex]

Answer:

sinA = [tex]\frac{3}{5}[/tex]

Step-by-step explanation:

sinA = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{BC}{AC}[/tex] = [tex]\frac{21}{35}[/tex] = [tex]\frac{3}{5}[/tex]

How many index laws are there?

Answers

Answer:

There are three laws of indices.

Plz answer will give brainliest

Answers

These triangles are congruent by SAS, therefore HI and IJ will be the same length.

3v = v + 60

2v = 60

v = 30

Hope this helps!

1. 80 = -10b
2. 6 = 2n
3. -16r = 32

1.
2.
3.

Answers

Answer:

1. - 8

2. 3

3. - 2

Step-by-step explanation:

1.

80 = - 10b

- 10b = 80

b = 80 / - 10

b = - 8

2.

6 = 2n

2n = 6

n = 6 / 2

n = 3

3.

- 16r = 32

r = 32 / - 16

r = - 2

Answer:

1. b = - 8
2. n = 3
3. r = -16

Step-by-step explanation:

we’re trying to solve for each variable

1. 80 = -10b

Divide both sides by -10

80/-10 = -10b/-10

-8 = b

2. 6 = 2n

Divide both sides by 2

6/2 = 2/2n

3 = n

3. -16r = 32

Divide -16 by both sides

-16r/-16 = 32/-16

r = -16

Can someone please explain this?

Answers

Answer:

-35

Step-by-step explanation:

The circles are what we are multiplying together

The square is the product

2* -5 = -10

2*7 = 14

To find the missing box

7* -5 = -35

What should be subtracted from thrice the rational number -8/3 to get
5/2?

Answers

Answer: -21/2 or -10.5

Step-by-step explanation:

Let x be the number that is going to be subtracted from the rational number

3 × (-8/3) - x = 5/2 ⇒ Write the equation

-8 - x = 5/2 ⇒ Do multiplication

-8 - x + x = 5/2 +x ⇒ Add x on both sides

-8 = 5/2 + x ⇒ Simplify

-8 - 5/2 = 5/2 + x - 5/2 ⇒ Subtract 5/2 on both sides

x = -21/2 = -10.5 ⇒ Simplify

Hope this helps!! :)

Please let me know if you have any questions

In science class, Victor started an experiment using a solution with a temperature of

5°C. During the experiment, the change in the solution's temperature was

4°C. What was the final temperature of Victor's solution?
To solve the problem, Antonio added

5+(

4) and came up with an answer of

9°C. Is Antonio correct? Why or why not?

Answers

The temp was 4 because of him doing temp

The function h is defined by the following rule.
h(x) = 4x-1​

Answers

Answer:

-3  -13

-2  -9

2     7

3    11

5  19

Step-by-step explanation:

h(x) = 4x-1​

Let x = -3

h(-3) = 4(-3) -1 = -12-1 = -13

Let x = -2

h(-2) = 4(-2) -1 = -8-1 = -9

Let x = 2

h(-2) = 4(2) -1 = 8-1 = 7

Let x = 3

h(3) = 4(3) -1 = 12-1 = 11

Let x = 5

h(5) = 4(5) -1 = 20-1 = 17

[tex]\boxed{\large{\bold{\textbf{\textsf{{\color{blue}{Answer}}}}}}:)}[/tex]

[tex]\begin{gathered} \: \: \: \large{\boxed{\begin{array}{c|c}\boxed {\bf {X}} & \boxed {\bf {h(X)}} \\\\ \\ \text{-3} & \sf{-13} \\\\ \text{ -2} &\sf{-9} \\\\ \text{2}& \sf {7} \\\\ \text{3} &\sf {11} \\\\ \text{5} & \sf {19} \end {array}}}\end{gathered}[/tex]

Here,

h(x)=4x-1

h(-2)=4(-2)-1=-9h(-3)=4(-3)-1=-12h(2)=4(2)-1=7h(3)=4(3)-1=11h(5)=4(5)-1=19

14-8711
Josie parents opened a college
savings account that pays yearly
simple interest of 5.5%. They opened
the account with $500 and adds $50
each month to her account. How
much money is in her account at the
end of 4 years?
Record your answer and fill in the
bubbles on your answer document.
Be sure to use the correct place
value.

Answers

Answer:

$4,208.5

Step-by-step explanation:

The simple interest rate of the college savings account, R = 5.5%

The amount with which the account was opened, P = $500

The amount added each month to her account = $50

The amount in her account after 4 years = Required

The interest on each added $50 is given as follows;

50  × 0.055/12 × (1 + 2 + 3 + ... + 47) = 50  × 0.055/12 × (47/2)(1 + 47) = 258.5

The total amount deposited = 500 + 50 × 47 = $2,850

The total interest = 500×0.55×4 + 50  × 0.055/12 × (47/2)(1 + 47) = 1,358.5

The amount in her account at the end of 4 years, A, is given as follows

A = $2,850 + $1,358.5 = $4,208.5

Write the expression as a single function of alpha.
cos(180°-alpha)

Answers

Answer:

-cos α

is the answer-------

Please help me with this.. and tell correct answer..​

Answers

Answer:

Step-by-step explanation:

55 +80 + ∠C = 180   {Angle  sum property}

135 + ∠C = 180

∠C = 180 - 135

∠C = 45

The side opposite to the biggest angle is the longest side

Biggest angle is ∠B. So the longest side is AC

Smallest angle is ∠C. So, the shortest side is BA

Write in point-slope form, slope-intercept form, and standard form an equation that passes through (-1,2) with slope 4.

Answers

point slope form:y-2=4(x+1)

then distribute 4 and simplify y-2=4x+4 , y=4x+6 is the slope -y intercept form

then, move 4x on the left side, you get -4x+y=6 , multiply every term by -1, you get 4x-y=-6 which is standard form.

can i get some help. did it 3 times and still not sure.

Answers

Answer:

18

Step-by-step explanation:

The height of the cone is 8, and the diameter is 3. This means that the radius is 3/2, or 1.5. We can plug everything into the formula (using 3 for pi):

[tex]\frac{3(1.5)^2(8)}{3}[/tex]

We can cancel out the 3 from the numerator and the denominator, so we are left with 1.5^2 times 8. 1.5 squared is equal to 2.25, and 2.25 times 8 is equal to 18.

Find the zeroes of the following quadratic polynomials and verify the relationship between
the zeroes and the coefficients.
(i)4u^2+8u​

Answers

Answer:

Hello,

Step-by-step explanation:

Since 4u²+8u=4u(u+2)

Zeroes ={0,-2}

Coefficients={4,8}

But i don't know the relationship.

Does anyone know how to do these?

Answers

Answer:

D.

Step-by-step explanation:

f(x) = [tex]\sqrt[3]{4x}[/tex]

g(x) = 2x + 3

[tex]\frac{f}{g}[/tex] (x)  = 'f' divided by 'g'

[tex]\frac{\sqrt[3]{4x} }{2x+3}[/tex]    Substitute.

x cannot be -[tex]\frac{3}{2}[/tex] because that would create a zero in the denominator.

That's a no-no.

It makes it 'undefined'

Is the height of these students a function of their wrist circumference?

Yes because as wrist circumference increases height also increases.
O Yes because a line can be fit to these data to predict other pairings.
No because the height of 151 cm is paired with two wrist circumferences.
O No because the wrist circumference of 16 cm is paired with two heights,

Answers

No because the wrist circumference of 16 cm is paired with two heights

hope this helps

Create a system of linear equations with one solution. In your final answer, include the system of equations and the graphs of the lines.

Answers

Answer:

System of equations

[tex]x + y = 5[/tex]

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

[tex](x,y) = (3,2)[/tex] --- solution

See attachment for graph

Step-by-step explanation:

Solving (a): Linear equations with 1 solution

The only condition to this is that, the system must have 1 solution.

Other than that, there is no other condition.

A linear equation is represented as:

[tex]ax + by= c[/tex]

For the equation to have 1 solution;

[tex]a_1 * b_2 \ne a_2 * b_1[/tex]

And example of such equation is:

[tex]x + y = 5[/tex]

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

Solving (b): The graph

See attachment for graph

The solution is the point of intersection of both lines of the graph. So, we have:

[tex](x,y) = (3,2)[/tex]

Please help!! I have no idea how to do this

Answers

Answer:

i have also no idea but plz mark me as brainlist

Help me please answer my question

Answers

Answer:

1

Step-by-step explanation:

Every time he turns the crank, the boxes go up the same amount of feet. Therefore the correct answer is one.

Answer:

y = x

constant is 1

Step-by-step explanation:


Need helppppp asappp

Answers

8 and 4 are the answers! :)
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