0 votes 0 votes 9. Find the coefficient of x lO in the power series of each of these functions. a. (x^2 +x^4 +x^6 +x^8 + .. . )(x^3 +x^6 +x^9 + .. ·)(x^4 + x^8 +X^12 + ... ) b. (I +x^2+x^4+x^6+ x^8+ ... )(1 +x^4+X^8+X^I2 + ... ) (I +x^6 +x^12 +x^18 + ... ) Mathematical Logic generating-functions discrete-mathematics combinatory + – rahul sharma 5 asked Jun 10, 2017 • retagged Jun 27, 2017 by Arjun rahul sharma 5 1.1k views answer comment Share Follow See all 8 Comments See all 8 8 Comments reply sid1221 commented Jun 12, 2017 reply Follow Share For last it is 500 combination ...may be help you 0 votes 0 votes rahul sharma 5 commented Jun 12, 2017 reply Follow Share We need to manually count here all the combinations ,am i correct?Like the way you have written 0 votes 0 votes sid1221 commented Jun 12, 2017 reply Follow Share yes we have to calculate coeffient of x^10 so we make x^10 by given x terms .. 0 votes 0 votes iarnav commented Jul 20, 2017 reply Follow Share bro is there a straightway shortcut by which you written 1 for all 5 cases or you calculated using binomial formula? 0 votes 0 votes sid1221 commented Jul 20, 2017 reply Follow Share see first i wrote 1+x^2+x^4... =1/1-x^2 , which is sum of infinite gp .. then i used 1/(1-x)^n = n-1+rcr x^r , here x= x^2 , r vary according to coefficient .... 0 votes 0 votes iarnav commented Jul 21, 2017 reply Follow Share Thanks so much Sir, for your reply and the formula. May you please tell me from where you got this formula/? 0 votes 0 votes sid1221 commented Jul 21, 2017 reply Follow Share rosen chapter 6 , .. you will get all open and closed form of generating function ... https://gateoverflow.in/85604/generalized-permutation-and-combination for more clearification 0 votes 0 votes akash.dinkar12 commented Sep 12, 2018 reply Follow Share what is the answer of 9 A?? 0 votes 0 votes Please log in or register to add a comment.