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KengaRu [80]
4 years ago
6

Find the exact value of cos 75 by using a sum or difference formula

Mathematics
1 answer:
anygoal [31]4 years ago
3 0
Cos 75 = 45 + 30

Formula: cos 45 x cos 30 - sin 45 x sin 30

Cos 45 = root 2 / 2
Cos 30 = root 3 / 2
Sin 45 = root 2 / 2
Sin 30 = 1 / 2

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The denominator of a fraction is four more than three times the numerator. If both numerator and denominator are increased by fo
Oksanka [162]

Let the numerator = x. Then,

The fraction is x/(3x+4).

If both the numerator and denominator are increased by 4, the fraction will be (x+4)/(3x+8), which, according to the question is equal to 9/25. So,

(x+4)/(3x+8) = 9/25

25(x+4) = 9(3x+8)

25x + 100 = 27x + 72

2x = 28

x = 14

Thus, the numerator is 14 and the denominator is (3*14 + 4), which is equal to 46. So the fraction is 14/46.

7 0
3 years ago
A square is put together by two triangles. The hypotenuse is 11 cm and width of 8 cm. find the height of triangle?
Aleks [24]
You can use the pythagorean theorem. Make sure that you put the measurements in the right places though. Since 11 is the measure of the hypotenuse, 11 has to be c. When you plug in the information that you have, it should look like this:
8^2 + b^2 = 11^2

Square 8 and 11. 
64 + b^2 = 121

Subtract 64 from 121
121 - 64 = 57

The new equation is:
b^2 = 57

Now take the square root of both sides to get b by itself. 
b = about 7.5

Answer: The height of the triangle is 7.5

***** Note: I rounded the answer ********************************************
4 0
3 years ago
7. $6,000 is invested in an account that earns 4.5% annual interest, compounded quarterly. What is the
Dafna11 [192]

Answer:

The value of account after 8 years is $8580  

Step-by-step explanation:

Given in question as :

The principal that invested in an account = $6,000

The annual interest rate  compounded quarterly = 4.5%

Time period = 8 years

Now from compound Interest method for quarterly .

Amount = Principal ( 1 + \frac{Rate}{4 \times 100})^{4 \times Time}

Or,Amount = $6,000 ( 1 + \frac{4.5}{4 \times 100})^{4 \times 8}

Or, Amount = $6,000 (1.430)

∴ Amount = $8580  

Hence the value of account after 8 years is $8580   Answer

5 0
4 years ago
A single die is rolled twice. Find the probability of rolling an even number the first time and a number greater than 3 the seco
IceJOKER [234]

Events

• A: an even number is rolled in the first time

,

• B: a number greater than 3 is rolled the second time

The probability of rolling an even number is:

\begin{gathered} P(A)=\frac{\text{ number of favorable outcomes}}{\text{ total possible outcomes}} \\ P(A)=\frac{3}{6} \\ P(A)=\frac{1}{2} \end{gathered}

The probability of rolling a number greater than 3 is:

\begin{gathered} P(B)=\frac{\text{ number of favorable outcomes}}{\text{ total possible outcomes}} \\ P(B)=\frac{3}{6} \\ P(B)=\frac{1}{2} \end{gathered}

Events A and B are independent, then the probability of one happening after the other is:

\begin{gathered} \text{ P(A and B) = }P(A)\cdot P(B) \\ \text{ Substituting with the values previously found:} \\ \text{ P(A and B) = }\frac{1}{2}\cdot\frac{1}{2} \\ \text{ P(A and B) = }\frac{1}{4} \end{gathered}

8 0
1 year ago
What is the slope of this line
ivolga24 [154]

Answer:

1/2

Step-by-step explanation:

The slope is 1/2. The line goes down one and 2 left.

6 0
4 years ago
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