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3 years ago

Where did the formula of sphere comes from

Mathematics

1 answer:

Elina [12.6K]3 years ago

7 0

Answer:

Archimedes was the first to derive this formula.

Step-by-step explanation:

You might be interested in

Round to the nearest 10<br><br> 9,491<br> 12,876

ddd [48]

Answer:

9,490 & 12,880

Step-by-step explanation:

9491 rounded to the nearest 10 would round down to 9490

12876 rounded to the nearest 10 would round up to 12880

6 0

2 years ago

The length of a rectangle is 7 centimeters longer than twice its width. If the perimeter is 68 centimeters, find the width and l

vredina [299]

Answer:

Length-25

Width-9

Step-by-step explanation:

x-width

2x+7-height

6x+14=68

-14 -14

6x=54

x=9

6 0

3 years ago

Read 2 more answers

1 in 4 families now owes money on a

Alecsey [184]

"a rise of a quarter from last year" means the percentage went up by 25%

x = old value

x + 25% of x = x + 0.25x = 1.25x = new value = 0.25 since "1 in 4" means 1/4 = 0.25

So,

1.25x = 0.25

x = 0.25/1.25

x = 0.2

x = 2/10

x = 1/5

Answer: The fraction of families that owed money is 1/5, or 1 in 5.

4 0

3 years ago

If this particular arithmetic sequence, a7=34 and a15=74. What is the value of a21

Ilya [14]

This is an arithmetic sequence, meaning, to get the next term, you simply add some value to the current one, namely the "common difference" "d".

now, we know the 17th term is 34, let's go to the 15term then

34 + d
34 + d + d
34 + d + d + d
34 + d + d + d + d
34 + d + d + d + d + d
34 + d + d + d + d + d + d
34 + d + d + d + d + d + d + d
34 + d + d + d + d + d + d + d + d

now, notice, we got to the 15th term, which is 34 + d + d + d + d + d + d + d + d, or namely 34 + 8d, it just so happen we know is 74, therefore,

$\bf 34+8d=74\implies 8d=40\implies d=\cfrac{40}{8}\implies \boxed{d=5}$

ok, now that we know what the common difference is, let's find the first term in the sequence using the 7th term of 34,

$\bf n^{th}\textit{ term of an arithmetic sequence}\\\\
a_n=a_1+(n-1)d\qquad 
\begin{cases}
n=n^{th}\ term\\
a_1=\textit{first term's value}\\
d=\textit{common difference}\\
----------\\
n=7\\
d=5\\
a_7=34
\end{cases}
\\\\\\
a_7=a_1+(7-1)5\implies 34=a_1+(7-1)5
\\\\\\
34=a_1+30\implies \boxed{4=a_1}$

and now let's use those 2 found folks, to get the 21st term,

$\bf n^{th}\textit{ term of an arithmetic sequence}\\\\
a_n=a_1+(n-1)d\qquad 
\begin{cases}
n=n^{th}\ term\\
a_1=\textit{first term's value}\\
d=\textit{common difference}\\
----------\\
a_1=4\\
d=5\\
n=21
\end{cases}
\\\\\\
a_{21}=4+(21-1)5\implies a_{21}=4+100\implies a_{21}=104$

3 0

3 years ago

2.16 ÷ 4 hurry its a timed test thank you!

vlada-n [284]

Answer:

0.54

Step-by-step explanation:

2.16/14 = 0.54

8 0

3 years ago