JEE Class main Answered
if an= -2/(4n^2)-(16n)+(15), [(4n^2)-(16n)+(15) dis entire thing is the denominator)]
then:
opt a) a1+a2+....+a10= 20/51
opt b) a1+a2+.....a10=30/51
opt c) a1+a2+......a25=50/141
opt d) a1+a2+.....a25=60/141
Its more than one ans type q, pls tell me a detailed explanation on how to do it as i din understand
Asked by joanmaria916 | 08 Jul, 2023, 16:37: PM
TO find the sum of first 10 terms when an = -2/(4n2 - 16n + 15)
![4 straight n squared minus 16 straight n plus 15 equals 4 straight n squared minus 10 straight n minus 6 straight n plus 15 equals 2 straight n left parenthesis 2 straight n minus 5 right parenthesis minus 3 left parenthesis 2 straight n minus 5 right parenthesis equals left parenthesis 2 straight n minus 5 right parenthesis left parenthesis 2 straight n minus 3 right parenthesis
rightwards double arrow straight a subscript straight n equals fraction numerator negative 2 over denominator left parenthesis 2 straight n minus 5 right parenthesis left parenthesis 2 straight n minus 3 right parenthesis end fraction equals negative open square brackets fraction numerator 1 over denominator 2 straight n minus 5 end fraction minus fraction numerator 1 over denominator 2 straight n minus 3 end fraction close square brackets equals fraction numerator 1 over denominator 2 straight n minus 3 end fraction minus fraction numerator 1 over denominator 2 straight n minus 5 end fraction
straight a subscript 1 equals fraction numerator 1 over denominator negative 1 end fraction minus fraction numerator 1 over denominator negative 3 end fraction comma space straight a subscript 2 equals 1 over 1 minus fraction numerator 1 over denominator negative 1 end fraction comma space straight a subscript 3 equals 1 third minus 1 over 1 comma straight a subscript 4 equals 1 fifth minus 1 third comma... straight a subscript 10 equals 1 over 17 minus 1 over 15
rightwards double arrow straight a subscript 1 plus straight a subscript 2 plus straight a subscript 3 plus... plus straight a subscript 10 equals negative 1 plus 1 third plus 1 plus 1 plus 1 third minus 1 plus 1 fifth minus 1 third plus... plus 1 over 17 minus 1 over 15
space space space space space equals 1 third plus 1 over 17
space space space space space equals 20 over 51](https://images.topperlearning.com/topper/tinymce/cache/9b1ec71ad7348707eab126f9a5846a74.png)
Answered by Renu Varma | 13 Jul, 2023, 12:06: PM
JEE main - Maths
Asked by vishalsarap0022 | 19 May, 2024, 10:30: AM
JEE main - Maths
Asked by obravickykumar50 | 07 May, 2024, 09:27: AM
JEE main - Maths
Asked by vishwajeetsinghrajput2018 | 17 Mar, 2024, 00:27: AM
JEE main - Maths
Asked by sabeenashaik575 | 09 Jan, 2024, 09:53: AM
JEE main - Maths
Asked by kunmunkumar08032008 | 08 Oct, 2023, 13:15: PM
JEE main - Maths
Asked by nitinsolanki14102001 | 16 Sep, 2023, 15:01: PM
JEE main - Maths
Asked by joanmaria916 | 08 Jul, 2023, 16:37: PM
JEE main - Maths
Asked by vishnuramrs07 | 30 May, 2023, 21:05: PM