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3 years ago

Find the sum of the first 12 terms of the sequence. Show all work for full credit. 1, -4, -9, -14, . . . (2 points)

Mathematics

2 answers:

nordsb [41]3 years ago

5 0

<h2>Answer:</h2>

<h2>Step-by-step explanation:</h2>

See the attached image

My name is Ann [436]3 years ago

4 0

<u>Answer:</u>

$S_n=$ -348

<u>Step-by-step explanation:</u>

We are given the following arithmetic sequence and we are to find the sum of its first 12 terms:

1, -4, -9, -14, . . .

For that, we will use the formula for the sum of the arithmetic mean:

$S_n=\frac{n}{2} (a_1+a_n)$

We know the value of the first term ( $a_n$ ) but we need to find the value of $a_{12}$ . So we will use the following formula:

$a_{12}=a_1+(n-1)d$

$a_{12}=(-4)+(12-1)(5)$

$a_{12}=-59$

Substituting these values in the sum formula to get:

$S_n=\frac{12}{2} (1+(-59))$

$S_n=$ -348

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liq [111]

Answer:

The side c needs to be 12.85 for the triangle to have greatest perimeter

Step-by-step explanation:

We are given;

b = 13

a = 15

Angle at b: B = 55°

Let's find side c.

Using the law of cosines,we have;

b² = a² + c² - 2ac•cos(B)

13² = 15² + c² - 2•15•c•cos(55)

169 = 225 + c² - 30c•cos(55)

c² - 30c•cos(55) + 225 - 169 = 0

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Using quadratic formula;

c = [-(-17.208) ± √((-17.208)² - (4•1•56)]/2(1)

c = [17.208 ± √(296.115 - 224)]/2

c = 8.604 ± 4.246

To have the greater perimeter, we need the larger value of c, thus we will use the positive sign and ignore the negative one ;

Thus,

c = 8.604 + 4.246 = 12.85

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3 years ago

What are the leading coefficient, constant term and degree, if any, of the algebraic expression 1+x^3

MA_775_DIABLO [31]

The degree refers to the x to some exponent where the highest exponent is the degree.
Degree: 3
The leading coefficient is the coefficient of the term we just found(of the highest exponent)
Leading Coefficient: 1
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Constant Term: 1

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3 years ago

You fly a hot air balloon 3.5 miles above the ground. What is the measure of BD⌢, the portion of Earth that you can see? Round y

STatiana [176]

Answer:

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