If tan(x+y)=2 and tanx=1.find tan^-1?

Answer 1

tan(x+y) = (tanx + tany)/(1 - tanxtany)
2 = (1 + tany)/(1 - tany)
1 + tany = 2 - 2tany
3tany = 1
tany = 1/3

Don't know what inverse you want when you ask for tan^-1

if tanx = 1
x = π/4
if tany = 1/3
y = .32175..
if tan(x+y) = 2
x + y = 1.107148..

verified in π/4 + .32175 = 1.107..