All Questions Topic List
Arithmetic Questions
Previous in All Question Next in All Question
Previous in Arithmetic Next in Arithmetic
Question Number 31229 by abdo imad last updated on 03/Mar/18
simplifyAn=Cn1+2Cn2+3Cn3+...+nCnn.
Commented by abdo imad last updated on 05/Mar/18
letintroducethepolynomialp(x)=∑k=0nCnkxkwehavep(x)=(x+1)n⇒p′(x)=n(x+1)n−1fromanothersidep′(x)=∑k=1nkCnkxk−1andwehaveAn=p′(1)=n2n−1.
Terms of Service
Privacy Policy
Contact: info@tinkutara.com