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3 years ago

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The average rate of change from x = 1 to x = 3 of f(x)=x^3 - 4 is __________

1 answer:

Vikki [24]3 years ago

8 0

This looks confusing

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Algebraic expression the sum of 12 and k

USPshnik [31]

The answer is 12+k because sum means addition and it says 12 and k therefore you and 12 and k together and the algebraic expression would be 12+k

7 0

3 years ago

Determine formula of the nth term 2, 6, 12 20 30,42

nalin [4]

Check the forward differences of the sequence.

If $\{a_n\} = \{2,6,12,20,30,42,\ldots\}$ , then let $\{b_n\}$ be the sequence of first-order differences of $\{a_n\}$ . That is, for n ≥ 1,

$b_n = a_{n+1} - a_n$

so that $\{b_n\} = \{4, 6, 8, 10, 12, \ldots\}$ .

Let $\{c_n\}$ be the sequence of differences of $\{b_n\}$ ,

$c_n = b_{n+1} - b_n$

and we see that this is a constant sequence, $\{c_n\} = \{2, 2, 2, 2, \ldots\}$ . In other words, $\{b_n\}$ is an arithmetic sequence with common difference between terms of 2. That is,

$2 = b_{n+1} - b_n \implies b_{n+1} = b_n + 2$

and we can solve for $b_n$ in terms of $b_1=4$ :

$b_{n+1} = b_n + 2$

$b_{n+1} = (b_{n-1}+2) + 2 = b_{n-1} + 2\times2$

$b_{n+1} = (b_{n-2}+2) + 2\times2 = b_{n-2} + 3\times2$

and so on down to

$b_{n+1} = b_1 + 2n \implies b_{n+1} = 2n + 4 \implies b_n = 2(n-1)+4 = 2(n + 1)$

We solve for $a_n$ in the same way.

$2(n+1) = a_{n+1} - a_n \implies a_{n+1} = a_n + 2(n + 1)$

Then

$a_{n+1} = (a_{n-1} + 2n) + 2(n+1) \\ ~~~~~~~= a_{n-1} + 2 ((n+1) + n)$

$a_{n+1} = (a_{n-2} + 2(n-1)) + 2((n+1)+n) \\ ~~~~~~~ = a_{n-2} + 2 ((n+1) + n + (n-1))$

$a_{n+1} = (a_{n-3} + 2(n-2)) + 2((n+1)+n+(n-1)) \\ ~~~~~~~= a_{n-3} + 2 ((n+1) + n + (n-1) + (n-2))$

and so on down to

$a_{n+1} = a_1 + 2 \displaystyle \sum_{k=2}^{n+1} k = 2 + 2 \times \frac{n(n+3)}2$

$\implies a_{n+1} = n^2 + 3n + 2 \implies \boxed{a_n = n^2 + n}$

6 0

2 years ago

Four and sixty eight thousandths in decimal form

kumpel [21]

Answer:4.068

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

Jessica needs to make a necklace for 3 of her friends, including her. she wants to use 4.5 inches of string for each necklace. s

hoa [83]

Answer:

She can make two necklaces with 10 inches. 8 more inches

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

the length of a rectangular patio is 8 feet less than twice its width. the area of the patio is 280 square feet. find the dimens

jolli1 [7]

Answer:

The length of the rectangle 'l' = 20

The width of the rectangle 'w' = 14

Step-by-step explanation:

<u>Explanation</u>:-

Let 'x' be the width

Given data the length of a rectangular patio is 8 feet less than twice its width

2x-8 = length

The area of rectangle = length X width

Given area of rectangle = 280 square feet

x(2x-8) = 280

2(x)(x-4) =280

x(x-4) =140

x^2 -4x -140=0

x^2-14x+10x-140=0

x(x-14)+10(x-14)=0

(x+10)(x-14) =0

x = -10 and x = 14

we can choose only x =14

The width of the rectangle 14

The length of the rectangle 2x-8 = 2(14)-8 = 28 -8 =20

The length of the rectangle 'l' = 20

The width of the rectangle 'w' = 14

6 0

3 years ago