" 20."(1)/(x(x+1)^(2))

If x+sqrt(x^(2)-1)+(1)/(x+sqrt(x^(2)+1))=20 then x^(2)+sqrt(x^(4)-1)+(1)/(x^(2)+sqrt(x^(4)-1))=

Find the coefficient of x^(18) in the polynomial f(x)=(1+x)^(20)+x(1+x)^(19)+x^(2)(1+x)^(18)+.........+x^(18)(1+x)^(2)

Find the coefficient of x^(20) in (x^(2)+2+(1)/(x^(2)))^(-5)(1+x^(2))^(40)

The coefficient of x^(20) in the expansion of (1+x^(2))^(40)*(x^(2)+2+(1)/(x^(2)))^(-5) is:

(1)/(sqrt(x^(2)-8x-20))

If 64x^(2) + (1)/(64 x^(2)) = 20 , then 8x - (1)/(4x) can be "_______"

Find the sum of 20 terms of the series (x+(1)/(2))+(3x-(1)/(6))+(5x+(1)/(18))+....