maths.free › Combinatorics & Graph Theory › Recurrences and generating functions

Recurrences and generating functions

Solving recurrence relations, and encoding a sequence as a power series.

A recurrence defines aₙ from earlier terms; a generating function Σ aₙ xⁿ packs the whole sequence into one function whose algebra does the counting. Picture it: the Fibonacci numbers growing by the golden ratio each step. Think it: linear recurrences with constant coefficients are solved exactly like constant-coefficient differential equations, a characteristic polynomial.

कार्यरत उदाहरण · fib(25)

Number-Theory · Sequences

Fib(25)

25

चरणानुक्रमे

  1. F_0 = 0,; F_1 = 1

    Each Fibonacci number is the sum of the two before it.

  2. F_{2} = F_{1} + F_{0} = 1

  3. F_{3} = F_{2} + F_{1} = 2

  4. F_{4} = F_{3} + F_{2} = 3

  5. F_{5} = F_{4} + F_{3} = 5

  6. F_{6} = F_{5} + F_{4} = 8

  7. F_{7} = F_{6} + F_{5} = 13

  8. F_{8} = F_{7} + F_{6} = 21

  9. \vdots

  10. F_{24} = F_{23} + F_{22} = 46368

  11. F_{25} = F_{24} + F_{23} = 75025

उत्तर उघडा
F_{25} = 75025

आता तुम्ही प्रश्न निवडा, किंवा स्वतःचा प्रश्न टाइप करा किंवा रेखाटून दाखवा. प्रत्येक टप्प्यात, चित्रे आहेत, तुम्ही विचारण्याआधी उत्तर लपवलेले आहे.

स्वतःचे कार्य चालू ठेवा

मोफत खाते प्रत्येक शिकवणी वर टिपण्णी जोडते, तुम्ही पूर्ण केलेल्या गोष्टीचा नोंदवही, तुमच्या सोडविलेल्या समस्या एका ठिकाणी, आणि या पानाच्या विषयी तुम्ही विचारू शकता अशा शिक्षकाला. गणित स्वतःच सर्वांसाठी खुले आहे, दाखलन झालेले असो किंवा नसो.

नोंदणी करा दाखलन

येथे वापरलेले चिन्ह

Tap any symbol for the full definition, a picture, and what every letter in it means.

कसे कराल: Recurrences and generating functions

  1. Each Fibonacci number is the sum of the two before it.

लोक विचारतात ते प्रश्न

Permutation or combination?

Ask whether order matters. A lock code is a permutation (order matters); a hand of cards is a combination (it does not).

What is a graph in this sense?

Dots (vertices) joined by lines (edges), not a plot. Road maps, social networks and molecules are graphs; questions like "is there a route" and "how few colours" are graph theory.

अधिक माहिती Combinatorics & Graph Theory

The counting principlesPigeonhole principle and inclusion, exclusionBinomial coefficients and Pascal's triangleGraphs: vertices, edges, degreesPaths, cycles, trees, Euler and HamiltonColouring and planar graphs