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-BARSIC- [3]
3 years ago
9

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

Mathematics
1 answer:
nikitadnepr [17]3 years ago
5 0

Answer:

cosA = - \frac{7}{25}

Step-by-step explanation:

Using the double angle identity

cos2A = 2cos²A - 1 , then

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

cosA = 2 × (\frac{3}{5} )² - 1

        = 2 × \frac{9}{25} - 1

       = \frac{18}{25} - \frac{25}{25}

       = - \frac{7}{25}

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(4v^3-3v^2)+(3v^3+6v^2-9v)​
Alexxandr [17]

Answer:

7v^3+3v^2-9v

Step-by-step explanation:

This is the simplified version

3 0
4 years ago
Need this now<br>need it----------<br>----------​
lina2011 [118]

Answer: X = kuv/ (u+v)

that means that x(u+v)/(uv) = k, a constant. so you want x such that,

x(3+3)/(3*3) = 3(3+1)/(3*1)

x=6

8 0
3 years ago
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Dafna11 [192]
30 b/c 60 x 1/2= 30

Answer= 30
7 0
3 years ago
Read 2 more answers
Solve the equation <br>8(4- x) = 7x + 2<br>x=​
Jet001 [13]

Answer: x=2

Step-by-step explanation:

Expand.

32−8x=7x+2

Add 8x to both sides.

32=7x+2+8x

Simplify  7x+2+8x7x+2+8x  to  15x+215x+2.

32=15x+2

Subtract 22 from both sides.

32−2=15x

Simplify  32−2  to  30.

30=15x

Divide both sides by 15.

30/15=x

Simplify 30/15 to 2

2=x

Switch sides.

x=2

7 0
4 years ago
Please help me. This is real confusing. ​
katrin2010 [14]

Answer:

1st problem: b) A=2500(1.01)^{12t}

2nd problem:  c) A=2500e^{.12t}

Step-by-step explanation:

1st problem:

The formula/equation you want to use is:

A=P(1+\frac{r}{n})^{nt}

where

t=number of years

A=amount he will owe in t years

P=principal (initial amount)

r=rate

n=number of times the interest is compounded per year t.

We are given:

P=2500

r=12%=.12

n=12 (since there are 12 months in a year and the interest is being compounded per month)

A=2500(1+\frac{.12}{12})^{12t}

Time to clean up the inside of the ( ).

A=2500(1+.01)^{12t}

A=2500(1.01)^{12t}

----------------------------------------------------

2nd Problem:

Compounded continuously problems use base as e.

A=Pe^{rt}

P is still the principal

r is still the rate

t is still the number of years

A is still the amount.

You are given:

P=2500

r=12%=.12

Let's plug that information in:

A=2500e^{.12t}.

6 0
3 years ago
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