Please wait...
Contact Us
Contact
Need assistance? Contact us on below numbers

For Study plan details

10:00 AM to 7:00 PM IST all days.

For Franchisee Enquiry

OR

or

Thanks, You will receive a call shortly.
Customer Support

You are very important to us

For any content/service related issues please contact on this number

9372462318 / 9987178554

Mon to Sat - 10 AM to 7 PM

ques 28

Asked by chandanbr6004 19th November 2017, 5:32 PM
Answered by Expert
Answer:
begin mathsize 16px style sum from straight i equals 1 to straight n of straight a subscript straight i straight b subscript straight i plus sum from straight i equals 1 to straight n of open parentheses straight a subscript straight i minus straight a close parentheses squared
equals sum from straight i equals 1 to straight n of straight a subscript straight i open parentheses 1 minus straight a subscript straight i close parentheses plus sum from straight i equals 1 to straight n of open parentheses straight a subscript straight i minus straight a close parentheses squared..... open curly brackets straight b subscript straight i equals 1 minus straight a subscript straight i close curly brackets
equals sum from straight i equals 1 to straight n of straight a subscript straight i minus sum from straight i equals 1 to straight n of straight a squared subscript straight i plus sum from straight i equals 1 to straight n of straight a squared subscript straight i minus 2 straight a sum from straight i equals 1 to straight n of straight a subscript straight i plus straight a squared sum from straight i equals 1 to straight n of 1
equals sum from straight i equals 1 to straight n of straight a subscript straight i minus 2 straight a sum from straight i equals 1 to straight n of straight a subscript straight i plus straight a squared sum from straight i equals 1 to straight n of 1
equals na minus 2 straight a cross times na plus straight a squared straight n
equals na open parentheses 1 minus straight a close parentheses..... left parenthesis 1 right parenthesis
now
nb equals sum from straight i equals 1 to straight n of straight b subscript straight i
nb equals sum from straight i equals 1 to straight n of open parentheses 1 minus straight a subscript straight i close parentheses
nb equals straight n minus na
straight b equals 1 minus straight a....... sub space in space left parenthesis 1 right parenthesis
ans space equals space nab


end style
Answered by Expert 5th December 2017, 4:16 PM
Rate this answer
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10

You have rated this answer /10

Your answer has been posted successfully!
JEE QUESTION ANSWERS

Chat with us on WhatsApp