



 
Anne, We don't 'divide by infinity' because infinity is not really a number. What we do is divide by a large number and let that large number keep growing (approaching infinity). We call this taking limits as the number tends to infinity. If you take 0 and divide by 100, what would you get? If you take 0 and divide by 1000, what would you get? If you take 0 and divide by 10000, what would you get? And so on. Regardless of what large number we're dividing by our answer is 0 and by letting this large number increase (as much as we please, tending to infinity) the answer is still 0. Thus the 'answer' to your question is 0. You might also look at my answer to a questiion about 1/infinity. Penny  


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