" (b) "tan^(-1)a+cot^(-1)(a+1)=tan^(-1)(a^(2)+a+1)

cot(tan^(-1)a+cot^(-1)a)

tan^(-1)(cot x)-tan^(-1)(cot2x)=

Prove that : 2 tan^(-1) (cosec tan^(-1) x - tan cot^(-1) x) = tan^(-1) x

Prove that : 2 tan^(-1) (cosec tan^(-1) x - tan cot^(-1) x) = tan^(-1) x

The value of tan^(-1)(1/2tan2A) +tan^(-1)(cotA)+tan^(-1)(cot^3A), for 0 lt A lt pi//4 is a) tan^(-1)2 b) tan^(-1)(cotA) c) 4 tan^(-1)(1) d) 2 tan^(-1)(2)

2"tan"(tan^(-1)(x)+tan^(-1)(x^3)),w h e r ex in R-{-1,1}, is equal to (2x)/(1-x^2) t(2tan^(-1)x) tan(cot^(-1)(-x)-cot^(-1)(x)) "tan"(2cot^(-1)x)

2"tan"(tan^(-1)(x)+tan^(-1)(x^3)),w h e r ex in R-{-1,1}, is equal to (2x)/(1-x^2) t(2tan^(-1)x) tan(cot^(-1)(-x)-cot^(-1)(x)) "tan"(2cot^(-1)x)

Prove that: tan^(-1)(1)/(7)+tan^(-1)(1)/(13)=tan^(-1)(2)/(9)tan^(-1)+tan^(-1)(1)/(5)+tan^(-1)(1)/(8)=(pi)/(4)tan^(-1)(3)/(4)+tan^(-1)(3)/(5)-tan^(-1)(8)/(19)=(pi)/(4)tan^(-1)(1)/(5)+tan^(-1)(1)/(7)+tan^(-1)(1)/(3)+tan^(-1)(1)/(8)=(pi)/(4)cot^(-1)7+cot^(-1)8+cot^(-1)18=cot^(-1)(1)/(13)