Question 1203180
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The problem says  A = k*d^2 (surface area of a sphere SA varies directly as the square of its diameter, d).


Then it asks "If the surface area is doubled, by what ratio must the diameter be altered?".


So we write

    {{{A}}} = {{{k*d^2}}},     (1)

    {{{2A}}} = {{{k*D^2}}}     (2)


and divide equation (2) by equation (1).  We get then

    2 = {{{(D/d)^2}}},

which implies

    {{{D/d}}} = {{{sqrt(2)}}} = 1.414213562...


In wording form, it means that if the surface area of a sphere is doubled, then the ratio 
of the new diameter to the original diameter is  {{{D/d}}} = {{{sqrt(2)}}} = 1.414213562...,
which gives the answer to the problem's question.
</pre>

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Solved, with complete explanations.


This solution (or something very similar) is what they do expect to get from you.


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Regarding your solution, notice that 


&nbsp;&nbsp;&nbsp;&nbsp;- you do unnecessary calculations;

&nbsp;&nbsp;&nbsp;&nbsp;- you do not get a general answer; 

&nbsp;&nbsp;&nbsp;&nbsp;- you use centimeters and square centimeters instead of millimeters and square millimeters.


So, you play some your own game, but do not provide the EXPECTED solution.


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Dear visitor,


I have read your comment regarding this problem, which you submitted to the @greenestamps' personal page.

Especially attentively, I read that part of your comment, which related to my solution.

It helped me to understand better your style of thinking and your style of making communication/discussion.

Be sure that I will make all my necessary conclusions from it for the future.