Question

sin + cos > 1 prove ?

Answer 1

L.h.s SniA+cosA=1
R.H.s proved

Answer 2

Let (C) be a unit circle, and M∈(C). Also, we will denote ∠IOM as θ (see the diagram). From the unit circle definition, the coordinates of the point M are (cosθ,sinθ). And so, ¯OC is cosθ and ¯OS is sinθ. Therefore, OM=√¯OC2+¯OS2=√cos2θ+sin2θ. Since M lies in the unit circle, OM is the radius of that circle, and by definition, this radius is equal to 1. It immediately follows that: cos2θ+sin2θ=1