JEE Main202227 Jun 2022Morning ShiftMathematicsSequences and SeriesActual
If x = ∑ n = 0 ∞ a n , y = ∑ n = 0 ∞ b n , z = ∑ n = 0 ∞ c n , where a , b , c are in A.P. and a < 1 , b < 1 , c < 1 , a b c ≠ 0 , then
Options
- Ax , y , z are in A.P.
- Bx , y , z are in G.P.
- C1 x , 1 y , 1 z are in A.P.
- D1 x + 1 y + 1 z = 1 - a + b + c
Correct answer
C. 1 x , 1 y , 1 z are in A.P.
Step-by-step solution
x = 1 + a + a 2 = . . . . . . x = 1 1 - a ⇒ a = 1 - 1 x y = 1 1 - b ⇒ b = 1 - 1 y z = 1 1 - c ⇒ c = 1 - 1 z a , b , c are in A.P. ⇒ 1 - 1 x , 1 - 1 y , 1 - 1 z are in A.P. ⇒ - 1 x , - 1 y , - 1 z are in A.P. ⇒ 1 x , 1 y , 1 z are in A.P.