trigonometric function 0° < θ < 90°，0 < sinθ，cosθ < 1，0 < tanθ，tanθ ∈ ∞
lim sinθ = 1 ( θ →90° )
lim sinθ = 0 ( θ → 0° )
lim cosθ = 1 ( θ → 0° )
lim cosθ = 0 ( θ →90° )
lim tanθ = 0 ( θ → 0° )
lim tanθ = ∞ ( θ → 90° )
sinθ，cosθ，tanθ ≠ 0，1 ，tanθ ∈ ∞ナノデ、xy plan function デハ使用スベキデハ無イ。
T.theodor 2022.7.16
