To solve the problem of finding the number of regions formed by all chords of an (n)-gon inscribed in a circle (with no three chords intersecting at a single point inside), we use the following formula:
Key Insight
The number of regions (R(n)) is determined by three components:
- The initial region (the circle itself: (1)).
- The number of chords ((\binom{n}{2}), since each pair of points forms a chord).
- The number of intersections inside the circle ((\binom{n}{4}), since each set of 4 points creates exactly one intersection).
Formula
[R(n) = 1 + \binom{n}{2} + \binom{n}{4}]
Expanding the binomial coefficients:
[R(n) = 1 + \frac{n(n-1)}{2} + \frac{n(n-1)(n-2)(n-3)}{24}]
Example Calculations
- For (n=4): (1 + 6 + 1 = 8)
- For (n=5): (1 + 10 +5 =16)
- For (n=6): (1 +15 +15=31)
Answer: The number of regions is given by (1 + \binom{n}{2} + \binom{n}{4}) (substitute the value of (n) from the problem to get the numerical result).
If the problem specifies (n=6), the answer is (\boxed{31}). (Adjust based on the actual (n) in the image.)
Assuming the common problem with (n=6), the final answer is:
(\boxed{31})


作者声明:本文包含人工智能生成内容。