KVPY2015MathematicsSequences and Series
The largest perfect square that divides 2014³-2013³+2012³-2011³+ .+2³-1³ is
Options
- A1²
- B2²
- C1007²
- D2014²
Correct answer
C. 1007²
Step-by-step solution
S=2014³-2013³+2012³-2011³+ .+2³-1³ _ t=1 ²⁰¹⁴ r²+ _ t=1 ¹⁰⁷(2 r-1)(2 r) S = _ r=1 ²⁰¹⁴ r²+ _ r=1 ¹⁰⁰⁷ (4 r²-2 r ) S = (2014)(2015)(4029) 6 + 4 1007 1008 2015 6 - 2 1007 1008 2 =(1007)² 4031