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Dovator [93]
3 years ago
9

Find S15 for the series -1 + -3 + -5 + -7 +...

Mathematics
1 answer:
Ber [7]3 years ago
8 0
Hello :
the sum is  arithmetic secquence of common -diff is :
(-7)-(-5) =(-5)-(-3) = (-3)-(-1) =-2 = d
  the first term is : a1 = -1
<span>the formula of the sum :  S= (n/2)(a1 +an)
n is number of term       an = a1+(n-1)d</span>
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You randomly choose one of the tiles shown below. What is the probability of choosing a number less than 5? *
Bad White [126]

Answer:

1/3

Step-by-step explanation:

There are 12 tiles. There are 4 numbers less than 5, so the probability would be 4/12 so we simplify it to 1/3

7 0
3 years ago
At the park there is a pool shaped like a circle. A ring-shaped path goes around the pool. Its inner diameter is 22yd and its ou
jeka94
First, we need to think about what we're actually solving for: the area of the path. To find this, we can find the area of the whole thing, minus the area of the pool.

The diagram would look something like the picture I attached. We know that to find the area of a circle, you do πr^2. The radius is half of the diameter, so halve the diameters:

22/2 = 11 yards
32/2 = 16 yards

Then solve for the area of both circles.
π11^{2}= 121π ≈ <span>380.13 (area of the pool)</span>
π16^{2}= 256π ≈ <span>804.25 (area of the whole thing)
</span>
Next, subtract the area of the pool from the area of the whole thing to find the area of the walkway:
804.25 - 380.13 = 424.12 (area of the walkway)

Finally, divide the area of the walkway by 6 to see how many gallons of paint you'll need:

424.12 ÷ 6 ≈ 70.69

So you'll need 71 gallons of paint!

Hope I helped and let me know if you have any questions :)


6 0
4 years ago
What is the range of function y=√(-2cos^2x+3cosx-1)
Ugo [173]
Hello Friend,here is the solution for your question


<span>so the given function is </span>
y= √(-2cos²x+3cosx-1)
 i.e = √[-2(cos²x-3/2+1/2)]
i.e = √[-2(cosx-3/4)²-9/16+1/2]
i.e. = √[-2(cos-3/4)²-1/16]
i.e. = √[1/8-3(cosx=3/4)²]-----------(1)

Now here  in this equation is this quantity :-
<span>(cosx=3/4)²----------------(2)   is to it's minimum value then the whole equation </span>
<span>i.e. = √[1/8-3(cosx=3/4)²] will be maximum and vice versa </span>


And we know that cosx-3/4 will be minimum if cosx=3/4
<span>therefore put this in (1) we get </span>
(cosx=3/4)²=0    [ cosx=3/4]
<span>hence the minimum value of the quantity (cosx=3/4)² is 0 </span>

<span>put this in equation (1) </span>
we get ,
i.e. = √[1/8-3(cosx=3/4)²]
   =√[1/8-3(0)]        [ because minimum value of of the quantity (cosx=3/4)² is 0 ]
     =√1/8
      =1/(2√2)

<span>this is the maximum value now to find the minimum value </span>

<span>since this is function of root so the value of y will always be ≥0 </span>

<span>hence the minimum value of the function y is 0 </span>


<span>Therefore, the range of function </span>y is [0,1/(2√2)]


__Well,I have explained explained each and every step,do tell me if you don't understand any step._

8 0
3 years ago
Math 1125 – Unit 1 ~ Gunkelman Practice for Section 1.5 The Basics of Graphing Prep Skills The table represents the Seven Summit
marta [7]

According to the table, the highest mountain in Africa is Mt. Kilimanjaro with 19,340 feet in height. The highest mountain in Antarctica is Vinson Massif with 16,864 feet in height.

Then, we subtract

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7 0
2 years ago
Can someone please help me?
Nonamiya [84]

you have to read the bottom link for the answer key

3 0
3 years ago
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