Let f (x) = {arctan [1 / (x-1)], X not equal to 1,0, x = 1. Find the limit of F (x), X tends to 1 minus, and the limit of F (x), X tends to 1 plus

Let f (x) = {arctan [1 / (x-1)], X not equal to 1,0, x = 1. Find the limit of F (x), X tends to 1 minus, and the limit of F (x), X tends to 1 plus

When x → 1 +, 1 / (x-1) → + ∞, arctan (1 / (x-1) → π / 2, Lin (x → 1 +) f (x) = π / 2,
When x → 1 -, 1 / (x-1) → - ∞, arctan (1 / (x-1) → - π / 2, Lin (x → 1 +) f (x) = - π / 2