Find the values of following . (a) `(tan^(2)37(1)/(7)^(@)+1)/(tan^(2)37(1)/(2)^(@)-1)` (b) `(3 tan^(2)5^(@)-1)/(3tan5^(@)-tan^(3)5^(@))`

Find the value of (tan^(2)37(1)/(2)^(@)+1)/(tan^(2)37(1)/(2)^(@)-1) .

Find the value of the following : tan (2 tan^(-1) . 1/5)

Find the value of the following tan(2 tan^-1(1/5))

Find the principal values of the following (i) tan^(-1) (tan. (2pi)/(3)) (ii) tan^(-1) (tan (-6))

Find the principal values of the following (i) tan^(-1) (tan. (2pi)/(3)) (ii) tan^(-1) (tan (-6))

tan^(-1)3-tan^(-1)2=tan^(-1)(1/7)

tan^(-1)3-tan^(-1)2=tan^(-1)(1/7)

Find the sum of each of the following series: (i) tan^(-1)((1)/(x^(2)+x+1))+tan^(-1)((1)/(x^(2)+3x+3))+tan^(-1)((1)/(x^(2)+5X+7))+tan^(-1)((1)/(x^(2))+7x+13))...... upto n.