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3 years ago

Find the exact value of : cos(2 arctan(4/3))

1 answer:

7 0

Cos(2 arctan(4/3)) = cos(2 arccos(3/5)) = cos^2(arccos(3/5)) - sin^2(arccos(3/5)) = cos^2(arccos(3/5)) - sin^2(arcsin(4/5)) = (3/5)^2 - (4/5)^2 = 9/25 - 16/25 = -7/25.

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Use the quadratic formula to solve the equation. If necessary, round to the nearest hundredth.

Rzqust [24]

Answer:

a = 6 or 9

Step-by-step explanation:

The "a", "b", and "c" of the quadratic formula are the coefficients of a², a, and the constant term in the given equation:

... a = 2, b = -30, c = 108

Then the quadratic formula tells you the solutions are ...

... (-b ± √(b² -4ac))/(2a)

... = (-(-30) ± √((-30)² -4(2)(108)))/(2(2))

... = (30 ± √(900 -864))/4

... = (30 ± √36)/4

... = (30 ± 6)/4 = {24, 36}/4

... = {6, 9}

_____

The <em>a</em> variable should not be confused with the "a" that is used to name the coefficient of the square of the variable in the quadratic formula. If it is too confusing, rewrite one or the other. For example, you could write ...

... The solution to pa² +qa +r = 0 is ... a = (-q ± √(q²-4pr))/(2p)

where p=2, q=-30, r=108 in the given equation.

5 0

3 years ago

A radio station advertises a contest with ten cash prizes totaling $5510. There is to be a $100 difference between each successi

My name is Ann [436]

Answer:

option C

c. least: $101

greatest: $1001

Step-by-step explanation:

A radio station advertises a contest with ten cash prizes totaling $5510. There is to be a $100 difference between each successive prize.

Sum of 10 prizes = 5510

100 is the difference. there is a common difference d=100

So its a arithmetic sequence

the sum formula for arithmetic sequence is

$S_n = \frac{n}{2}(2a_1 +(n-1)d)$

Sn = 5510, n=10 n d= 100 we need to find out first term a1

$5510 = \frac{10}{2}(2a_1 +(10-1)100)$

5510 = 5 (2a1 + 900)

5510 = 10a1 + 4500

Subtract 4500 on both sides

1010= 10a1

divide by 10 on both sides

a1 = 101

so first term that is least term is 101

To find out greatest term we use formula

$a_n = a_1 + (n-1) d$

a(10) = 101 + (10-1)100

= 101 + 900= 1001

greatest is 1001

4 0

3 years ago

Need to also show work but confused

Levart [38]

Answer:

S = 2

Step-by-step explanation:

1st step: Simplify both sides of the equation

4/5 s - 3/4 s = 1/10

4/5 s + -3/4 s = 1/10

(4/5 s + -3/4 s) = 1/10 (combine like terms)

1/20 s = 1/10

step 2: multiply both sides by 20

20 * (1/20 s) = 20 * (1/10)

s = 2

Hope this helped!

7 0

3 years ago

M(5,7) is the midpoint of RS the coordinates of S are (6,9) what are the coordinates of R

MaRussiya [10]

Answer:

(4,5) i believe

7 0

3 years ago

Read 2 more answers

You have a goal to save $250. You have saved $160? What percent of your goal have you reached?

FromTheMoon [43]

The answer is 64 percent

8 0

3 years ago