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It's really difficult for me! 1、 Observe the following numbers and explore their regularity -1,1/2 ,-1/3 ,1/4 ,-1/5 ,1/6. ① Fill in the number 7, 8 and 9; ② What is the number 2006? If the list goes on indefinitely, which number will be closer to?
Positive and negative separated, the denominator is a natural number increasing
-1/7,1/8,-1/9
1/2006
Because the denominator is infinitely large and the reciprocal is infinitely small, both positive and negative are infinitely close to 0
The general term is [(- 1) ^ n] / n
There are difficulties
Xiao Ming made eight cubes of the same size from a cube of 125 cubic centimeter
There are two schemes, one is not a square, the other is a circle. The area of the two schemes is compared
Write two irrational numbers with a sum of 4
1:
If the edge length is x cm, then (x ^ 3) * 8 = 125
2: Square, each side length: 48 divided by 4 for 12 meters, the area is 12 * 12 = 144 square meters
If it is round, the circumference of the circle is 48 = 3.14 * r * 2, D is the straight diameter, and the area is 3.14 * r square
Just compare it again
I'm counting six, I'm counting five, I'm counting five, I'm counting five, I'm guessing there are a few balloons between 80 and 100
The least common multiple of 6 and 5: 30
30 * 3 = 90 between 80 and 100
So there are 90 balloons
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