如何计算Pascal's Triangle
learn.whatIsHeading
Pascal's Triangle is a triangular array where each number is the sum of the two numbers directly above it. It encodes binomial coefficients, combinatorics, and the coefficients of binomial expansions. Named after Blaise Pascal (1623–1662) though known much earlier.
分步指南
- 1Row 0: 1 | Row 1: 1, 1 | Row 2: 1, 2, 1 | Row 3: 1, 3, 3, 1
- 2Entry C(n,k) = entry in row n, position k = n! / (k!(n−k)!)
- 3Binomial expansion: (a+b)^n coefficients are row n of the triangle
- 4Sum of row n = 2^n; diagonal sums give Fibonacci numbers
例题解析
输入
(x+y)^4
结果
1x⁴ + 4x³y + 6x²y² + 4xy³ + 1y⁴
Coefficients: Row 4 = 1,4,6,4,1
输入
Combinations C(5,2)
结果
10
Row 5, position 2 of Pascal's Triangle
准备好计算了吗?尝试免费的 Pascal's Triangle 计算器
自己尝试一下 →