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1 year ago

Write a rule for the nth term of the arithmetic sequence a8=-15 a17=-78

Mathematics

1 answer:

vivado [14]1 year ago

4 0

Answer:

Find the 40th term for the arithmetic sequence in which

a8=60 and a12=48 .

Substitute 60 for a8 and 48 for a12 in the formula

an=a1+(n−1)d to obtain a system of linear equations in terms of a1 and d .

a8=a1+(8−1)d→60=a1+7da12=a1+(12−1)d→48=a1+11d

Subtract the second equation from the first equation and solve for d .

12=−4d−3=d

Then 60=a1+7(−3) . Solve for a .

60=a1−2181=a1

Now use the formula to find a40 .

a40=81+39(−3)=81−117=−36 .

Step-by-step explanation:

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Find the values of x and y. Pls helpI’m helpless at math

Svetradugi [14.3K]

Answer:

x = 1

$y=\frac{\sqrt{3}}{2}$

Step-by-step explanation:

From the given right-angle triangle

The angle = ∠60°

The adjacent to the angle ∠60° is 1/2.

The opposite to the angle ∠60° is y.

The hypotenuse = x

Determining the value of x:

Using the trigonometric ratio

cos 60° = adjacent / hypotenuse

substituting adjacent = 1/2 and hypotenuse = x

$cos\:60^{\circ }=\:\:\frac{\frac{1}{2}}{x}$

$\cos \left(60^{\circ \:}\right)=\frac{1}{2x}$

$\frac{1}{2}=\frac{1}{2x}$ ∵ cos (60°) = 1/2

$2x=2$

Dividing both sides by 2

$\frac{2x}{2}=\frac{2}{2}$

Simplify

$x=1$

Thus, the value of hypotenuse x is:

x = 1

Determining the value of y:

Using the trigonometric ratio

sin 60° = opposite / hypotenuse

As we have already determined the value of hypotenuse x = 1

substituting opposite = y and hypotenuse = 1

sin 60° = y/1

y = 1 × sin 60°

$y=\frac{\sqrt{3}}{2}$ ∵ $\sin \left(60^{\circ \:}\right)=\frac{\sqrt{3}}{2}$

Therefore, the value of y is:

$y=\frac{\sqrt{3}}{2}$

Summary:

x = 1

$y=\frac{\sqrt{3}}{2}$

5 0

2 years ago

Will give Brainlest Answer please answer i need help

Rashid [163]

Answer:

C. {-1, 5, 8}

Step-by-step explanation:

Use each of the domain values in the function to see what the corresponding range value is.

f(-1) = 5 -3(-1) = 8

f(0) = 5 -3(0) = 5

f(2) = 5 -3(2) = -1

The range is the set of numbers {-1, 5, 8}.

_____

Additional comment

The values in a set are generally listed lowest to highest. The coefficient of x in the equation for f(x) is negative, meaning the lowest range value will correspond to the highest domain value. If you start by finding f(2) = -1, you immediately eliminate all answer choices except B and C.

Those choices differ only in the middle value, so you can tell which is correct by evaluating f(x) for the middle domain value: f(0) = 5. Only one answer choice has both -1 and 5 in the set.

(There are two answers here: how you work the problem, and how you game a multiple choice question.)

4 0

2 years ago

Simplify the expression

AleksAgata [21]

4m + 5

Remove the parenthesis and collect like terms

3m + m + 5 = (3m + m) + 5 = 4m + 5

3 0

3 years ago

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