Area of a Sphere?

rcpratt

Lifer
Jul 2, 2009
10,433
110
116
You should use a more precise value than 3.14. His answer is consistent with a more precise value for pi.
 

Murloc

Diamond Member
Jun 24, 2008
5,382
65
91
You mean surface area?
lol this.

Also don't get hung up on numbers, the pi value is approximated and the calculator approximates stuff too.
What must be right is the symbolic calculations. Unless the test asks for numeric values and they don't check how you arrived to the results.
 

olds

Elite Member
Mar 3, 2000
50,053
709
126
Area inside a sphere is volume. Area on the outside of a sphere is surface area. Then there's the area outside the sphere but within another confined space.

"Area" alone is a bad term to use in this regard.
OK, I did see it referred to as "SA".
Thanks.
 

IronWing

No Lifer
Jul 20, 2001
69,006
26,883
136
Area inside a sphere is volume. Area on the outside of a sphere is surface area. Then there's the area outside the sphere but within another confined space.

"Area" alone is a bad term to use in this regard.
You take that back! You'll confuse Olds.
 

IronWing

No Lifer
Jul 20, 2001
69,006
26,883
136
I have a different formula for volume: V=4/3 Pi R2
Haven't worked it though.
For an extra credit problem in HS calculus class I had to derive that formula except I did it correctly and came up with R^3.

Initially the teacher wouldn't give me credit because he was expecting students to get to the answer using shells and I came at it using disks.
 
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SphinxnihpS

Diamond Member
Feb 17, 2005
8,368
25
91
Area inside a sphere is volume. Area on the outside of a sphere is surface area. Then there's the area outside the sphere but within another confined space.

"Area" alone is a bad term to use in this regard.

Yes, but it's more incorrect to say area when meaning volume, so good faith dictates that we take this mistake as the omission of surface rather than the confusion between area and volume, negating the the need for the clarifying question, at least until further idiocy is detected in this specific regard.

In other words, asking him if he means surface area or volume is more asinine than him simply leave the word surface out of his sentence.
 

Phoenix86

Lifer
May 21, 2003
14,643
9
81
Yes, but it's more incorrect to say area when meaning volume, so good faith dictates that we take this mistake as the omission of surface rather than the confusion between area and volume, negating the the need for the clarifying question, at least until further idiocy is detected in this specific regard.

In other words, asking him if he means surface area or volume is more asinine than him simply leave the word surface out of his sentence.
I'd be hard pressed to disagree, however I would also not put it past some teachers to make mistakes or use improper wording.
 

olds

Elite Member
Mar 3, 2000
50,053
709
126
As someone else already noted (kinda), the correct equation for volume of a sphere is V = (4/3)*pi*r^3.

Oops, I have 3 written down but typed 2. (As much as you can type on a Kindle.)