AP EAMCET201822 Apr 2018Morning ShiftMathematicsSequences and SeriesActual
If (x- 3 ), x, (x+ 3 ) are in a harmonic progression, then x=
Options
- A3 2
- B1
- C3 2
- D3 2
Correct answer
D. 3 2
Step-by-step solution
(d) It is given that, (x- 3 ) x, (x+ 3 ) are in H.P. aligned & = 2 (x- 3 ) (x+ 3 ) (x- 3 )+ (x+ 3 ) & & x= (x) (x- 3 )+ (x+ 3 ) & x= 2 ( ^2 x- ^2 3 ) 2 x 3 & ^2 x 3 = ^2 x- ^2 3 & ^2 x (1- 3 )= ^2 3 & ^2 x (1- 3 )= (1- ^2 3 ) & ^2 x (1- 3 )= (1- 3 ) (1+ 3 ) & ^2 x=1+ 3 & ^2 x=2 ^2 6 ^2 x=2 ( 3 2 )^2 & ^2 x=2 3 4 ^2 x= 3 2 & x= 3 2 . & aligned