Math question. tan(x)=-1 and tan(y)=2 find tan(x+y) and tan(x-y)?

Question

please show steps.

Answer 1

1)

Given data : tanx = -1 , tany = 2

Formula : tan(x+y) = [tanx + tany] / [ 1 - tanx tany]

Substitute : tanx = -1 and tany = 2

tan(x+y) = [-1 + 2] / [ 1 -(-1)(2)]

= [1] / [1 +2]

= 1/3

Solution : tan(x+y) = 1/3.

Answer 2

2)

Given data : tanx = -1 , tany = 2

Formula : tan(x-y) = [tanx - tany] / [ 1 + tanx tany]

Substitute : tanx = -1 and tany = 2

tan(x-y) = [-1 - 2] / [ 1 +(-1)(2)]

= [-3] / [1 - 2]

= (-3)/(-1)

= 3

Solution : tan(x-y) = 3