All categories

2 years ago

PLEASE HELP!!!!!! 20 POINTS!!!!!

Mathematics

1 answer:

Advocard [28]2 years ago

5 0

Answer:

-18.703

Step-by-step explanation:

a₁=-28(-1/2)¹⁻¹

r=-1/2

a₁=-28

r=-1/2

S₉=a₁ $\frac{1-r^{9} }{1-r}$

S₉=-28 $\frac{1-(\frac{1}{2})^{9} }{1-(\frac{1}{2}) }$

S₉= $-\frac{1197}{64}$

S₉=-18 $\frac{45}{64}$ S₉=-18.703125

You might be interested in

I am 21 years old my father is 3 times my age how old eill i be when my father is 40

DENIUS [597]

Answer:

Well the answer is 13.3 so 13 years old

Step-by-step explanation:

(F,Y) = (63,21)

Y3=F so F/3=y

F= 40

Y=?

40/3=Y

40/3=13.3

4 0

2 years ago

Read 2 more answers

Solve -2/3x > 8 or -2/3x < 4.

vekshin1

<h3>Answer: Choice C</h3>

{x | x < -12 or x > -6}

=========================================================

Explanation:

Let's solve the first inequality for x.

(-2/3)x > 8

-2x > 8*3

-2x > 24

x < 24/(-2)

x < -12

The inequality sign flips when we divide both sides by a negative value.

Let's do the same for the second inequality.

(-2/3)x < 4

-2x < 4*3

-2x < 12

x > 12/(-2)

x > -6

The conclusion of each section is that x < -12 or x > -6 which points us to <u>choice C</u> as the final answer.

Side note: The intervals x < -12 and x > -6 do not overlap in any way. There's a gap between the two pieces. We consider these intervals to be disjoint. The number line graph is below.

8 0

2 years ago

I need help please???

zimovet [89]

Answer:

(-7 and 3) (-5 and 1) (-3 and -1)

Step-by-step explanation:

If you add all of them you get -4.

4 0

3 years ago

Read 2 more answers

Calculus piecewise function.

Kipish [7]

Part A

The notation $\lim_{x \to 2^{+}}f(x)$ means that we're approaching x = 2 from the right hand side (aka positive side). This is known as a right hand limit.

So we could start at say x = 2.5 and get closer to 2 by getting to x = 2.4 then to x = 2.3 then 2.2, 2.1, 2.01, 2.001, etc

We don't actually arrive at x = 2 itself. We simply move closer and closer.

Since we're on the positive or right hand side of 2, this means we go with the rule involving x > 2

Therefore f(x) = (x/2) + 1

Plug in x = 2 to find that...

f(x) = (x/2) + 1

f(2) = (2/2) + 1

f(2) = 2

This shows $\lim_{x \to 2^{+}}f(x) = 2$

Then for the left hand limit $\lim_{x \to 2^{-}}f(x)$ , we'll involve x < 2 and we go for the first piece. So,

f(x) = 3-x

f(2) = 3-2

f(2) = 1

Therefore, $\lim_{x \to 2^{-}}f(x) = 1$

===============================================================

Part B

Because $\lim_{x \to 2^{+}}f(x) \ne \lim_{x \to 2^{-}}f(x)$ this means that the limit $\lim_{x \to 2}f(x)$ does not exist.

If you are a visual learner, check out the graph below of the piecewise function. Notice the gap or disconnect at x = 2. This can be thought of as two roads that are disconnected. There's no way for a car to go from one road to the other. Because of this disconnect, the limit doesn't exist at x = 2.

===============================================================

Part C

You'll follow the same type of steps shown in part A.

However, keep in mind that x = 4 is above x = 2, so we'll deal with x > 2 only.

So you'd only involve the second piece f(x) = (x/2) + 1

You should find that f(4) = 3, and that both left and right hand limits equal this value. The left and right hand limits approach the same y value. The limit does exist here. There are no gaps to worry about when x = 4.

===============================================================

Part D

As mentioned earlier, since $\lim_{x \to 4^{+}}f(x) = \lim_{x \to 4^{-}}f(x) = 3$ , this means the limit $\lim_{x \to 4}f(x)$ does exist and it's equal to 3.