BITSAT2011MathematicsSequences and SeriesActual
If ( p ^ th , q ^ th ) and ( r ^ th ) terms of H.P. are ( u , v , w ) respectively, then find the value of the expression ((q-r) v w+(r-p) w u+(p-q) u v ).
Options
- A2
- B0
- C4
- D8
Correct answer
B. 0
Step-by-step solution
Let H.P. be ( 1 a + 1 a + d + 1 a +2 ~d + ) ( aligned & u = 1 a +( p -1) d , v = 1 a +( q -1) d , & w = 1 a +( r -1) d a +( p -1) d = 1 u & a +( q -1) d = 1 v , a +( r -1) d = 1 w & ( q - r ) a +( p -1) d +( r - p ) a +( q -1) d + & = 1 u ( q - r )+ 1 v ( r - p )+ . (q-r) vw + . . = 0 aligned )