If `x_(1) x_(2) ...... x_(n)&(1)/(h_(1)) (1)/(h_(2)) ......(1)/(h_(n))` are two such that `x_(3)=h_(2)=8&x_(8)=h_(7)=20` then `x_(5)h_(10)` is

Let [x] = greatest integer le x . Suppose roots of the quadratic equation x^(2)+2(b-3)x+9=0 lie between -6 and 1 . Suppose (1)/(2),(1)/(h_(1)),(1)/(h_(2)),…,(1)/(h_(20)),(1)/([b]) are in A.P. and 2,a_(1),a_(2),…,a_(20) ,[b] are also in A.P., then a_(3)h_(18)=

If H_(n)=1+(1)/(2)+(1)/(3)+....+(1)/(n),AA n in N then H_(1)+H_(2)+H_(3)+......+H_(n)=

lim_(h rarr0)(1)/(h)((1)/(sqrt(x+h))-(1)/(sqrt(x)))

Lim_(h rarr0)(1)/(h)[(1)/(sqrt(x+h))-(1)/(sqrt(x))]

If x_(1), x_(2), x_(3) .................x_(n) are in H.P.then x_(1)x_(2)+x_(2)x_(3)+.......+x_(n-1)x_(n) =

If x_(1),x_(2),….x_(20) are in H.P then x_(1)x_(2)+x_(2)x_(3)+….+x_(19)x_(20) =

lim_(h rarr0)((x+h)^((1)/(n))-x^((1)/(n)))/(h)

Let a_(1),a_(2),...,a_(10) be in A.P.and h_(1),h_(2),h_(10) be a_(1)=h_(1)=2 and a_(10)=h_(10)=3, then a_(-)4h_(7) is 2 b.3 c.5 d.6