Find the value of the expression: `(1/(2^2-1)+1/(4^2-1)+1/(6^2-1)......+1/(20^2-1))`

Find the value of expression: sin(2tan^(-1)1/3)+cos(tan^(-1)2sqrt(2))

What is the value of the following expression? (1)/((2^(2)-1))+(1)/((4^(2)-1))+(1)/((6^(2)-1))+backslash+(1)/((20^(2)-1))(9)/(19) (b) (10)/(19)(c)(10)/(21) (d) (11)/(21)

Find the sum of the series 1/(3^2+1)+1/(4^2+2)+1/(5^2+3)+1/(6^2+4)+oo

Find the sum of the series 1/(3^2+1)+1/(4^2+2)+1/(5^2+3)+1/(6^2+4)+oo

Find the sum of the series 1/(3^2+1)+1/(4^2+2)+1/(5^2+3)+1/(6^2+4)+oo

Find the value of the expression : sin(2tan^-1(1/3)) + cos(Tan^-1 2sqrt2)

Find the value of x from the following expression: (7(1)/(2)-5(1)/(4))/(3(1)/(2)+x)-:((1)/(2)+1(1)/(4))/(1(1)/(5)+3(1)/(2))=0.6

Find the value of expression: sin(2tan^(-1)(1/3))+cos(tan^(-1)2sqrt(2))

Find the value of expression: sin(2tan^(-1)(1/3))+cos(tan^(-1)2sqrt(2))