If `y=(1)/(a+x)` then `y_(n)` is equal to :
(A) `((-1)^(n) n!)/((x+a)^(n+1))`
(B) `((-1)^(n) n!)/((x+a)^(n))`
(C)`((-1)^(n)a^(n))/((x+a)^(n+1))`
(D) `a^(n) n!`

If y=x^(n-1)lnx then x^2y_2+(3-2n)x y_1 is equal to (a) -(n-1)^2y (b) (n-1)^2y (c) -n^2y (d) n^2y

(d^n)/(dx^n)(logx)= ((n-1)!)/(x^n) (b) (n !)/(x^n) ((n-2)!)/(x^n) (d) (-1)^(n-1)((n-1)!)/(x^n)

(d^n)/(dx^n)(logx)=? (a) ((n-1)!)/(x^n) (b) (n !)/(x^n) (c) ((n-2)!)/(x^n) (d) (-1)^(n-1)((n-1)!)/(x^n)

If y=a x^(n+1)+b x^(-n),t h e nx^2(d^2y)/(dx^2) is equal to (a) n(n-1)y (b) n(n+1)y (c) n y (d) n^2y

If x_1, x_2, x_3,...... x _(2n) are in A.P , then sum _(r=1)^(2n) (-1)^(r+1) x_r^2 is equal to (a) (n)/((2n-1))(x _(1)^(2) -x _(2n) ^(2)) (b) (2n)/((2n-1))(x _(1)^(2) -x _(2n) ^(2)) (c) (n)/((n-1))(x _(1)^(2) -x _(2n) ^(2)) (d) (n)/((2n+1))(x _(1)^(2) -x _(2n) ^(2))

If y^(1/n)+y^(-1/n) = 2x then (x^2-1)y_2+xy_1 is equal to

The value of sum_(r=0)^n(a+r+a r)(-a)^r is equal to a. (-1)^n[(n+1)a^(n+1)-a] b. (-1)^n(n+1)a^(n+1) c. (-1)^n((n+2)a^(n+1))/2 d. (-1)^n(n a^n)/2

If (n^(n))/(n!)=(nx)/((n-1)!), x =

If y=a x^(n+1)+b x^(-n),t h e nx^2(d^2y)/(dx^2) is equal to n(n-1)y (b) n(n+1)y n y (d) n^2y

If y=a x^(n+1)+b x^(-n),t h e nx^2(d^2y)/(dx^2) is equal to n(n-1)y (b) n(n+1)y n y (d) n^2y