Let f (x) = 1 / 1 + SiNx, then its tangent equation at x = 0 is?

Let f (x) = 1 / 1 + SiNx, then its tangent equation at x = 0 is?

X = 0, f (x) = 1, that is, (0,1) is the tangent point
The derivative of F (x) is - cosx / (1 + SiNx) ^ 2, and its value at x = 0 is - 1,
From the geometric meaning of derivative, the slope of tangent is - 1
The tangent equation is x + Y-1 = 0